Package time

start := time.Now()
... operation that takes 20 milliseconds ...
t := time.Now()
elapsed := t.Sub(start)

Constants

These are predefined layouts for use in Time.Format and time.Parse. The reference time used in the layouts is the specific time:

Mon Jan 2 15:04:05 MST 2006

which is Unix time 1136239445. Since MST is GMT-0700, the reference time can be thought of as

01/02 03:04:05PM '06 -0700

To define your own format, write down what the reference time would look like formatted your way; see the values of constants like ANSIC, StampMicro or Kitchen for examples. The model is to demonstrate what the reference time looks like so that the Format and Parse methods can apply the same transformation to a general time value.

Some valid layouts are invalid time values for time.Parse, due to formats such as _ for space padding and Z for zone information.

Within the format string, an underscore _ represents a space that may be replaced by a digit if the following number (a day) has two digits; for compatibility with fixed-width Unix time formats.

A decimal point followed by one or more zeros represents a fractional second, printed to the given number of decimal places. A decimal point followed by one or more nines represents a fractional second, printed to the given number of decimal places, with trailing zeros removed. When parsing (only), the input may contain a fractional second field immediately after the seconds field, even if the layout does not signify its presence. In that case a decimal point followed by a maximal series of digits is parsed as a fractional second.

Numeric time zone offsets format as follows:

-0700  ±hhmm
-07:00 ±hh:mm
-07    ±hh

Replacing the sign in the format with a Z triggers the ISO 8601 behavior of printing Z instead of an offset for the UTC zone. Thus:

Z0700  Z or ±hhmm
Z07:00 Z or ±hh:mm
Z07    Z or ±hh

The recognized day of week formats are "Mon" and "Monday". The recognized month formats are "Jan" and "January".

The formats 2, _2, and 02 are unpadded, space-padded, and zero-padded day of month. The formats __2 and 002 are space-padded and zero-padded three-character day of year; there is no unpadded day of year format.

Text in the format string that is not recognized as part of the reference time is echoed verbatim during Format and expected to appear verbatim in the input to Parse.

The executable example for Time.Format demonstrates the working of the layout string in detail and is a good reference.

Note that the RFC822, RFC850, and RFC1123 formats should be applied only to local times. Applying them to UTC times will use "UTC" as the time zone abbreviation, while strictly speaking those RFCs require the use of "GMT" in that case. In general RFC1123Z should be used instead of RFC1123 for servers that insist on that format, and RFC3339 should be preferred for new protocols. RFC3339, RFC822, RFC822Z, RFC1123, and RFC1123Z are useful for formatting; when used with time.Parse they do not accept all the time formats permitted by the RFCs and they do accept time formats not formally defined. The RFC3339Nano format removes trailing zeros from the seconds field and thus may not sort correctly once formatted.

const (
    ANSIC       = "Mon Jan _2 15:04:05 2006"
    UnixDate    = "Mon Jan _2 15:04:05 MST 2006"
    RubyDate    = "Mon Jan 02 15:04:05 -0700 2006"
    RFC822      = "02 Jan 06 15:04 MST"
    RFC822Z     = "02 Jan 06 15:04 -0700" // RFC822 with numeric zone
    RFC850      = "Monday, 02-Jan-06 15:04:05 MST"
    RFC1123     = "Mon, 02 Jan 2006 15:04:05 MST"
    RFC1123Z    = "Mon, 02 Jan 2006 15:04:05 -0700" // RFC1123 with numeric zone
    RFC3339     = "2006-01-02T15:04:05Z07:00"
    RFC3339Nano = "2006-01-02T15:04:05.999999999Z07:00"
    Kitchen     = "3:04PM"
    // Handy time stamps.
    Stamp      = "Jan _2 15:04:05"
    StampMilli = "Jan _2 15:04:05.000"
    StampMicro = "Jan _2 15:04:05.000000"
    StampNano  = "Jan _2 15:04:05.000000000"
)

Common durations. There is no definition for units of Day or larger to avoid confusion across daylight savings time zone transitions.

To count the number of units in a Duration, divide:

second := time.Second
fmt.Print(int64(second/time.Millisecond)) // prints 1000

To convert an integer number of units to a Duration, multiply:

seconds := 10
fmt.Print(time.Duration(seconds)*time.Second) // prints 10s

const (
    Nanosecond  Duration = 1
    Microsecond          = 1000 * Nanosecond
    Millisecond          = 1000 * Microsecond
    Second               = 1000 * Millisecond
    Minute               = 60 * Second
    Hour                 = 60 * Minute
)

func After

func After(d Duration) <-chan Time

After waits for the duration to elapse and then sends the current time on the returned channel. It is equivalent to NewTimer(d).C. The underlying Timer is not recovered by the garbage collector until the timer fires. If efficiency is a concern, use NewTimer instead and call Timer.Stop if the timer is no longer needed.

func Sleep

func Sleep(d Duration)

Sleep pauses the current goroutine for at least the duration d. A negative or zero duration causes Sleep to return immediately.

func Tick

func Tick(d Duration) <-chan Time

Tick is a convenience wrapper for NewTicker providing access to the ticking channel only. While Tick is useful for clients that have no need to shut down the Ticker, be aware that without a way to shut it down the underlying Ticker cannot be recovered by the garbage collector; it "leaks". Unlike NewTicker, Tick will return nil if d <= 0.

type Duration

A Duration represents the elapsed time between two instants as an int64 nanosecond count. The representation limits the largest representable duration to approximately 290 years.

type Duration int64

func ParseDuration

func ParseDuration(s string) (Duration, error)

ParseDuration parses a duration string. A duration string is a possibly signed sequence of decimal numbers, each with optional fraction and a unit suffix, such as "300ms", "-1.5h" or "2h45m". Valid time units are "ns", "us" (or "µs"), "ms", "s", "m", "h".

10h0m0s
1h10m10s
There are 4210 seconds in 1h10m10s.
There are 1000 nanoseconds in 1µs.
There are 1.00e-06 seconds in 1µs.

func Since

func Since(t Time) Duration

Since returns the time elapsed since t. It is shorthand for time.Now().Sub(t).

func Until 1.8

func Until(t Time) Duration

Until returns the duration until t. It is shorthand for t.Sub(time.Now()).

func (Duration) Hours

func (d Duration) Hours() float64

Hours returns the duration as a floating point number of hours.

I've got 4.5 hours of work left.

func (Duration) Microseconds 1.13

func (d Duration) Microseconds() int64

Microseconds returns the duration as an integer microsecond count.

One second is 1000000 microseconds.

func (Duration) Milliseconds 1.13

func (d Duration) Milliseconds() int64

Milliseconds returns the duration as an integer millisecond count.

One second is 1000 milliseconds.

func (Duration) Minutes

func (d Duration) Minutes() float64

Minutes returns the duration as a floating point number of minutes.

The movie is 90 minutes long.

func (Duration) Nanoseconds

func (d Duration) Nanoseconds() int64

Nanoseconds returns the duration as an integer nanosecond count.

One microsecond is 1000 nanoseconds.

func (Duration) Round 1.9

func (d Duration) Round(m Duration) Duration

Round returns the result of rounding d to the nearest multiple of m. The rounding behavior for halfway values is to round away from zero. If the result exceeds the maximum (or minimum) value that can be stored in a Duration, Round returns the maximum (or minimum) duration. If m <= 0, Round returns d unchanged.

d.Round(   1ns) = 1h15m30.918273645s
d.Round(   1µs) = 1h15m30.918274s
d.Round(   1ms) = 1h15m30.918s
d.Round(    1s) = 1h15m31s
d.Round(    2s) = 1h15m30s
d.Round(  1m0s) = 1h16m0s
d.Round( 10m0s) = 1h20m0s
d.Round(1h0m0s) = 1h0m0s

func (Duration) Seconds

func (d Duration) Seconds() float64

Seconds returns the duration as a floating point number of seconds.

Take off in t-90 seconds.

func (Duration) String

func (d Duration) String() string

String returns a string representing the duration in the form "72h3m0.5s". Leading zero units are omitted. As a special case, durations less than one second format use a smaller unit (milli-, micro-, or nanoseconds) to ensure that the leading digit is non-zero. The zero duration formats as 0s.

1h2m0.3s
300ms

func (Duration) Truncate 1.9

func (d Duration) Truncate(m Duration) Duration

Truncate returns the result of rounding d toward zero to a multiple of m. If m <= 0, Truncate returns d unchanged.

d.Truncate(   1ns) = 1h15m30.918273645s
d.Truncate(   1µs) = 1h15m30.918273s
d.Truncate(   1ms) = 1h15m30.918s
d.Truncate(    1s) = 1h15m30s
d.Truncate(    2s) = 1h15m30s
d.Truncate(  1m0s) = 1h15m0s
d.Truncate( 10m0s) = 1h10m0s
d.Truncate(1h0m0s) = 1h0m0s

type Location

A Location maps time instants to the zone in use at that time. Typically, the Location represents the collection of time offsets in use in a geographical area. For many Locations the time offset varies depending on whether daylight savings time is in use at the time instant.

type Location struct {
    // contains filtered or unexported fields
}

Local represents the system's local time zone. On Unix systems, Local consults the TZ environment variable to find the time zone to use. No TZ means use the system default /etc/localtime. TZ="" means use UTC. TZ="foo" means use file foo in the system timezone directory.

var Local *Location = &localLoc

UTC represents Universal Coordinated Time (UTC).

var UTC *Location = &utcLoc

true

func FixedZone

func FixedZone(name string, offset int) *Location

FixedZone returns a Location that always uses the given zone name and offset (seconds east of UTC).

The time is: 10 Nov 09 23:00 UTC-8

func LoadLocation

func LoadLocation(name string) (*Location, error)

LoadLocation returns the Location with the given name.

If the name is "" or "UTC", LoadLocation returns UTC. If the name is "Local", LoadLocation returns Local.

Otherwise, the name is taken to be a location name corresponding to a file in the IANA Time Zone database, such as "America/New_York".

The time zone database needed by LoadLocation may not be present on all systems, especially non-Unix systems. LoadLocation looks in the directory or uncompressed zip file named by the ZONEINFO environment variable, if any, then looks in known installation locations on Unix systems, and finally looks in $GOROOT/lib/time/zoneinfo.zip.

2018-08-30 05:00:00 -0700 PDT

func LoadLocationFromTZData 1.10

func LoadLocationFromTZData(name string, data []byte) (*Location, error)

LoadLocationFromTZData returns a Location with the given name initialized from the IANA Time Zone database-formatted data. The data should be in the format of a standard IANA time zone file (for example, the content of /etc/localtime on Unix systems).

func (*Location) String

func (l *Location) String() string

String returns a descriptive name for the time zone information, corresponding to the name argument to LoadLocation or FixedZone.

type Month

A Month specifies a month of the year (January = 1, ...).

type Month int

const (
    January Month = 1 + iota
    February
    March
    April
    May
    June
    July
    August
    September
    October
    November
    December
)

func (Month) String

func (m Month) String() string

String returns the English name of the month ("January", "February", ...).

type ParseError

ParseError describes a problem parsing a time string.

type ParseError struct {
    Layout     string
    Value      string
    LayoutElem string
    ValueElem  string
    Message    string
}

func (*ParseError) Error

func (e *ParseError) Error() string

Error returns the string representation of a ParseError.

type Ticker

A Ticker holds a channel that delivers “ticks” of a clock at intervals.

type Ticker struct {
    C <-chan Time // The channel on which the ticks are delivered.
    // contains filtered or unexported fields
}

func NewTicker

func NewTicker(d Duration) *Ticker

NewTicker returns a new Ticker containing a channel that will send the time on the channel after each tick. The period of the ticks is specified by the duration argument. The ticker will adjust the time interval or drop ticks to make up for slow receivers. The duration d must be greater than zero; if not, NewTicker will panic. Stop the ticker to release associated resources.

func (*Ticker) Reset 1.15

func (t *Ticker) Reset(d Duration)

Reset stops a ticker and resets its period to the specified duration. The next tick will arrive after the new period elapses.

func (*Ticker) Stop

func (t *Ticker) Stop()

Stop turns off a ticker. After Stop, no more ticks will be sent. Stop does not close the channel, to prevent a concurrent goroutine reading from the channel from seeing an erroneous "tick".

type Time

A Time represents an instant in time with nanosecond precision.

Programs using times should typically store and pass them as values, not pointers. That is, time variables and struct fields should be of type time.Time, not *time.Time.

A Time value can be used by multiple goroutines simultaneously except that the methods GobDecode, UnmarshalBinary, UnmarshalJSON and UnmarshalText are not concurrency-safe.

Time instants can be compared using the Before, After, and Equal methods. The Sub method subtracts two instants, producing a Duration. The Add method adds a Time and a Duration, producing a Time.

The zero value of type Time is January 1, year 1, 00:00:00.000000000 UTC. As this time is unlikely to come up in practice, the IsZero method gives a simple way of detecting a time that has not been initialized explicitly.

Each Time has associated with it a Location, consulted when computing the presentation form of the time, such as in the Format, Hour, and Year methods. The methods Local, UTC, and In return a Time with a specific location. Changing the location in this way changes only the presentation; it does not change the instant in time being denoted and therefore does not affect the computations described in earlier paragraphs.

Representations of a Time value saved by the GobEncode, MarshalBinary, MarshalJSON, and MarshalText methods store the Time.Location's offset, but not the location name. They therefore lose information about Daylight Saving Time.

In addition to the required “wall clock” reading, a Time may contain an optional reading of the current process's monotonic clock, to provide additional precision for comparison or subtraction. See the “Monotonic Clocks” section in the package documentation for details.

Note that the Go == operator compares not just the time instant but also the Location and the monotonic clock reading. Therefore, Time values should not be used as map or database keys without first guaranteeing that the identical Location has been set for all values, which can be achieved through use of the UTC or Local method, and that the monotonic clock reading has been stripped by setting t = t.Round(0). In general, prefer t.Equal(u) to t == u, since t.Equal uses the most accurate comparison available and correctly handles the case when only one of its arguments has a monotonic clock reading.

type Time struct {
    // contains filtered or unexported fields
}

func Date

func Date(year int, month Month, day, hour, min, sec, nsec int, loc *Location) Time

Date returns the Time corresponding to

yyyy-mm-dd hh:mm:ss + nsec nanoseconds

in the appropriate zone for that time in the given location.

The month, day, hour, min, sec, and nsec values may be outside their usual ranges and will be normalized during the conversion. For example, October 32 converts to November 1.

A daylight savings time transition skips or repeats times. For example, in the United States, March 13, 2011 2:15am never occurred, while November 6, 2011 1:15am occurred twice. In such cases, the choice of time zone, and therefore the time, is not well-defined. Date returns a time that is correct in one of the two zones involved in the transition, but it does not guarantee which.

Date panics if loc is nil.

Go launched at 2009-11-10 15:00:00 -0800 PST

func Now

func Now() Time

Now returns the current local time.

func Parse

func Parse(layout, value string) (Time, error)

Parse parses a formatted string and returns the time value it represents. The layout defines the format by showing how the reference time, defined to be

Mon Jan 2 15:04:05 -0700 MST 2006

would be interpreted if it were the value; it serves as an example of the input format. The same interpretation will then be made to the input string.

Predefined layouts ANSIC, UnixDate, RFC3339 and others describe standard and convenient representations of the reference time. For more information about the formats and the definition of the reference time, see the documentation for ANSIC and the other constants defined by this package. Also, the executable example for Time.Format demonstrates the working of the layout string in detail and is a good reference.

Elements omitted from the value are assumed to be zero or, when zero is impossible, one, so parsing "3:04pm" returns the time corresponding to Jan 1, year 0, 15:04:00 UTC (note that because the year is 0, this time is before the zero Time). Years must be in the range 0000..9999. The day of the week is checked for syntax but it is otherwise ignored.

For layouts specifying the two-digit year 06, a value NN >= 69 will be treated as 19NN and a value NN < 69 will be treated as 20NN.

In the absence of a time zone indicator, Parse returns a time in UTC.

When parsing a time with a zone offset like -0700, if the offset corresponds to a time zone used by the current location (Local), then Parse uses that location and zone in the returned time. Otherwise it records the time as being in a fabricated location with time fixed at the given zone offset.

When parsing a time with a zone abbreviation like MST, if the zone abbreviation has a defined offset in the current location, then that offset is used. The zone abbreviation "UTC" is recognized as UTC regardless of location. If the zone abbreviation is unknown, Parse records the time as being in a fabricated location with the given zone abbreviation and a zero offset. This choice means that such a time can be parsed and reformatted with the same layout losslessly, but the exact instant used in the representation will differ by the actual zone offset. To avoid such problems, prefer time layouts that use a numeric zone offset, or use ParseInLocation.

2013-02-03 19:54:00 -0800 PST
2013-02-03 00:00:00 +0000 UTC
2006-01-02 15:04:05 +0000 UTC
2006-01-02 15:04:05 +0700 +0700
error parsing time "2006-01-02T15:04:05Z07:00": extra text: "07:00"

func ParseInLocation 1.1

func ParseInLocation(layout, value string, loc *Location) (Time, error)

ParseInLocation is like Parse but differs in two important ways. First, in the absence of time zone information, Parse interprets a time as UTC; ParseInLocation interprets the time as in the given location. Second, when given a zone offset or abbreviation, Parse tries to match it against the Local location; ParseInLocation uses the given location.

2012-07-09 05:02:00 +0200 CEST
2012-07-09 00:00:00 +0200 CEST

func Unix

func Unix(sec int64, nsec int64) Time

Unix returns the local Time corresponding to the given Unix time, sec seconds and nsec nanoseconds since January 1, 1970 UTC. It is valid to pass nsec outside the range [0, 999999999]. Not all sec values have a corresponding time value. One such value is 1<<63-1 (the largest int64 value).

func (Time) Add

func (t Time) Add(d Duration) Time

Add returns the time t+d.

start = 2009-01-01 12:00:00 +0000 UTC
start.Add(time.Second * 10) = 2009-01-01 12:00:10 +0000 UTC
start.Add(time.Minute * 10) = 2009-01-01 12:10:00 +0000 UTC
start.Add(time.Hour * 10) = 2009-01-01 22:00:00 +0000 UTC
start.Add(time.Hour * 24 * 10) = 2009-01-11 12:00:00 +0000 UTC

func (Time) AddDate

func (t Time) AddDate(years int, months int, days int) Time

AddDate returns the time corresponding to adding the given number of years, months, and days to t. For example, AddDate(-1, 2, 3) applied to January 1, 2011 returns March 4, 2010.

AddDate normalizes its result in the same way that Date does, so, for example, adding one month to October 31 yields December 1, the normalized form for November 31.

oneDayLater: start.AddDate(0, 0, 1) = 2009-01-02 00:00:00 +0000 UTC
oneMonthLater: start.AddDate(0, 1, 0) = 2009-02-01 00:00:00 +0000 UTC
oneYearLater: start.AddDate(1, 0, 0) = 2010-01-01 00:00:00 +0000 UTC

func (Time) After

func (t Time) After(u Time) bool

After reports whether the time instant t is after u.

year3000.After(year2000) = true
year2000.After(year3000) = false

func (Time) AppendFormat 1.5

func (t Time) AppendFormat(b []byte, layout string) []byte

AppendFormat is like Format but appends the textual representation to b and returns the extended buffer.

Time: 11:00AM

func (Time) Before

func (t Time) Before(u Time) bool

Before reports whether the time instant t is before u.

year2000.Before(year3000) = true
year3000.Before(year2000) = false

func (Time) Clock

func (t Time) Clock() (hour, min, sec int)

Clock returns the hour, minute, and second within the day specified by t.

func (Time) Date

func (t Time) Date() (year int, month Month, day int)

Date returns the year, month, and day in which t occurs.

year = 2000
month = February
day = 1

func (Time) Day

func (t Time) Day() int

Day returns the day of the month specified by t.

day = 1

func (Time) Equal

func (t Time) Equal(u Time) bool

Equal reports whether t and u represent the same time instant. Two times can be equal even if they are in different locations. For example, 6:00 +0200 and 4:00 UTC are Equal. See the documentation on the Time type for the pitfalls of using == with Time values; most code should use Equal instead.

datesEqualUsingEqualOperator = false
datesEqualUsingFunction = true

func (Time) Format

func (t Time) Format(layout string) string

Format returns a textual representation of the time value formatted according to layout, which defines the format by showing how the reference time, defined to be

Mon Jan 2 15:04:05 -0700 MST 2006

would be displayed if it were the value; it serves as an example of the desired output. The same display rules will then be applied to the time value.

A fractional second is represented by adding a period and zeros to the end of the seconds section of layout string, as in "15:04:05.000" to format a time stamp with millisecond precision.

Predefined layouts ANSIC, UnixDate, RFC3339 and others describe standard and convenient representations of the reference time. For more information about the formats and the definition of the reference time, see the documentation for ANSIC and the other constants defined by this package.

default format: 2015-02-25 11:06:39 -0800 PST
Unix format: Wed Feb 25 11:06:39 PST 2015
Same, in UTC: Wed Feb 25 19:06:39 UTC 2015

Formats:

Basic full date  "Mon Jan 2 15:04:05 MST 2006" gives "Wed Feb 25 11:06:39 PST 2015"
Basic short date "2006/01/02" gives "2015/02/25"
AM/PM            "3PM==3pm==15h" gives "11AM==11am==11h"
No fraction      "Mon Jan _2 15:04:05 MST 2006" gives "Wed Feb 25 11:06:39 PST 2015"
0s for fraction  "15:04:05.00000" gives "11:06:39.12340"
9s for fraction  "15:04:05.99999999" gives "11:06:39.1234"

Unix             "Mon Jan _2 15:04:05 MST 2006" gives "Sat Mar  7 11:06:39 PST 2015"
No pad           "<2>" gives "<7>"
Spaces           "<_2>" gives "< 7>"
Zeros            "<02>" gives "<07>"
Suppressed pad   "04:05" gives "06:39"

func (*Time) GobDecode

func (t *Time) GobDecode(data []byte) error

GobDecode implements the gob.GobDecoder interface.

func (Time) GobEncode

func (t Time) GobEncode() ([]byte, error)

GobEncode implements the gob.GobEncoder interface.

func (Time) Hour

func (t Time) Hour() int

Hour returns the hour within the day specified by t, in the range [0, 23].

func (Time) ISOWeek

func (t Time) ISOWeek() (year, week int)

ISOWeek returns the ISO 8601 year and week number in which t occurs. Week ranges from 1 to 53. Jan 01 to Jan 03 of year n might belong to week 52 or 53 of year n-1, and Dec 29 to Dec 31 might belong to week 1 of year n+1.

func (Time) In

func (t Time) In(loc *Location) Time

In returns a copy of t representing the same time instant, but with the copy's location information set to loc for display purposes.

In panics if loc is nil.

func (Time) IsZero

func (t Time) IsZero() bool

IsZero reports whether t represents the zero time instant, January 1, year 1, 00:00:00 UTC.

func (Time) Local

func (t Time) Local() Time

Local returns t with the location set to local time.

func (Time) Location

func (t Time) Location() *Location

Location returns the time zone information associated with t.

func (Time) MarshalBinary 1.2

func (t Time) MarshalBinary() ([]byte, error)

MarshalBinary implements the encoding.BinaryMarshaler interface.

func (Time) MarshalJSON

func (t Time) MarshalJSON() ([]byte, error)

MarshalJSON implements the json.Marshaler interface. The time is a quoted string in RFC 3339 format, with sub-second precision added if present.

func (Time) MarshalText 1.2

func (t Time) MarshalText() ([]byte, error)

MarshalText implements the encoding.TextMarshaler interface. The time is formatted in RFC 3339 format, with sub-second precision added if present.

func (Time) Minute

func (t Time) Minute() int

Minute returns the minute offset within the hour specified by t, in the range [0, 59].

func (Time) Month

func (t Time) Month() Month

Month returns the month of the year specified by t.

func (Time) Nanosecond

func (t Time) Nanosecond() int

Nanosecond returns the nanosecond offset within the second specified by t, in the range [0, 999999999].

func (Time) Round 1.1

func (t Time) Round(d Duration) Time

Round returns the result of rounding t to the nearest multiple of d (since the zero time). The rounding behavior for halfway values is to round up. If d <= 0, Round returns t stripped of any monotonic clock reading but otherwise unchanged.

Round operates on the time as an absolute duration since the zero time; it does not operate on the presentation form of the time. Thus, Round(Hour) may return a time with a non-zero minute, depending on the time's Location.

t.Round(   1ns) = 12:15:30.918273645
t.Round(   1µs) = 12:15:30.918274
t.Round(   1ms) = 12:15:30.918
t.Round(    1s) = 12:15:31
t.Round(    2s) = 12:15:30
t.Round(  1m0s) = 12:16:00
t.Round( 10m0s) = 12:20:00
t.Round(1h0m0s) = 12:00:00

func (Time) Second

func (t Time) Second() int

Second returns the second offset within the minute specified by t, in the range [0, 59].

func (Time) String

func (t Time) String() string

String returns the time formatted using the format string

"2006-01-02 15:04:05.999999999 -0700 MST"

If the time has a monotonic clock reading, the returned string includes a final field "m=±<value>", where value is the monotonic clock reading formatted as a decimal number of seconds.

The returned string is meant for debugging; for a stable serialized representation, use t.MarshalText, t.MarshalBinary, or t.Format with an explicit format string.

withNanoseconds = 2000-02-01 12:13:14.000000015 +0000 UTC
withoutNanoseconds = 2000-02-01 12:13:14 +0000 UTC

func (Time) Sub

func (t Time) Sub(u Time) Duration

Sub returns the duration t-u. If the result exceeds the maximum (or minimum) value that can be stored in a Duration, the maximum (or minimum) duration will be returned. To compute t-d for a duration d, use t.Add(-d).

difference = 12h0m0s

func (Time) Truncate 1.1

func (t Time) Truncate(d Duration) Time

Truncate returns the result of rounding t down to a multiple of d (since the zero time). If d <= 0, Truncate returns t stripped of any monotonic clock reading but otherwise unchanged.

Truncate operates on the time as an absolute duration since the zero time; it does not operate on the presentation form of the time. Thus, Truncate(Hour) may return a time with a non-zero minute, depending on the time's Location.

t.Truncate(  1ns) = 12:15:30.918273645
t.Truncate(  1µs) = 12:15:30.918273
t.Truncate(  1ms) = 12:15:30.918
t.Truncate(   1s) = 12:15:30
t.Truncate(   2s) = 12:15:30
t.Truncate( 1m0s) = 12:15:00
t.Truncate(10m0s) = 12:10:00

func (Time) UTC

func (t Time) UTC() Time

UTC returns t with the location set to UTC.

func (Time) Unix

func (t Time) Unix() int64

Unix returns t as a Unix time, the number of seconds elapsed since January 1, 1970 UTC. The result does not depend on the location associated with t. Unix-like operating systems often record time as a 32-bit count of seconds, but since the method here returns a 64-bit value it is valid for billions of years into the past or future.

2001-09-09 01:46:40 +0000 UTC
2001-09-09 01:46:40 +0000 UTC
2001-09-09 01:46:40 +0000 UTC
1000000000
1000000000000000000

func (Time) UnixNano

func (t Time) UnixNano() int64

UnixNano returns t as a Unix time, the number of nanoseconds elapsed since January 1, 1970 UTC. The result is undefined if the Unix time in nanoseconds cannot be represented by an int64 (a date before the year 1678 or after 2262). Note that this means the result of calling UnixNano on the zero Time is undefined. The result does not depend on the location associated with t.

func (*Time) UnmarshalBinary 1.2

func (t *Time) UnmarshalBinary(data []byte) error

UnmarshalBinary implements the encoding.BinaryUnmarshaler interface.

func (*Time) UnmarshalJSON

func (t *Time) UnmarshalJSON(data []byte) error

UnmarshalJSON implements the json.Unmarshaler interface. The time is expected to be a quoted string in RFC 3339 format.

func (*Time) UnmarshalText 1.2

func (t *Time) UnmarshalText(data []byte) error

UnmarshalText implements the encoding.TextUnmarshaler interface. The time is expected to be in RFC 3339 format.

func (Time) Weekday

func (t Time) Weekday() Weekday

Weekday returns the day of the week specified by t.

func (Time) Year

func (t Time) Year() int

Year returns the year in which t occurs.

func (Time) YearDay 1.1

func (t Time) YearDay() int

YearDay returns the day of the year specified by t, in the range [1,365] for non-leap years, and [1,366] in leap years.

func (Time) Zone

func (t Time) Zone() (name string, offset int)

Zone computes the time zone in effect at time t, returning the abbreviated name of the zone (such as "CET") and its offset in seconds east of UTC.

type Timer

The Timer type represents a single event. When the Timer expires, the current time will be sent on C, unless the Timer was created by AfterFunc. A Timer must be created with NewTimer or AfterFunc.

type Timer struct {
    C <-chan Time
    // contains filtered or unexported fields
}

func AfterFunc

func AfterFunc(d Duration, f func()) *Timer

AfterFunc waits for the duration to elapse and then calls f in its own goroutine. It returns a Timer that can be used to cancel the call using its Stop method.

func NewTimer

func NewTimer(d Duration) *Timer

NewTimer creates a new Timer that will send the current time on its channel after at least duration d.

func (*Timer) Reset 1.1

func (t *Timer) Reset(d Duration) bool

Reset changes the timer to expire after duration d. It returns true if the timer had been active, false if the timer had expired or been stopped.

For a Timer created with NewTimer, Reset should be invoked only on stopped or expired timers with drained channels.

If a program has already received a value from t.C, the timer is known to have expired and the channel drained, so t.Reset can be used directly. If a program has not yet received a value from t.C, however, the timer must be stopped and—if Stop reports that the timer expired before being stopped—the channel explicitly drained:

if !t.Stop() {
	<-t.C
}
t.Reset(d)

This should not be done concurrent to other receives from the Timer's channel.

Note that it is not possible to use Reset's return value correctly, as there is a race condition between draining the channel and the new timer expiring. Reset should always be invoked on stopped or expired channels, as described above. The return value exists to preserve compatibility with existing programs.

For a Timer created with AfterFunc(d, f), Reset either reschedules when f will run, in which case Reset returns true, or schedules f to run again, in which case it returns false. When Reset returns false, Reset neither waits for the prior f to complete before returning nor does it guarantee that the subsequent goroutine running f does not run concurrently with the prior one. If the caller needs to know whether the prior execution of f is completed, it must coordinate with f explicitly.

func (*Timer) Stop

func (t *Timer) Stop() bool

Stop prevents the Timer from firing. It returns true if the call stops the timer, false if the timer has already expired or been stopped. Stop does not close the channel, to prevent a read from the channel succeeding incorrectly.

To ensure the channel is empty after a call to Stop, check the return value and drain the channel. For example, assuming the program has not received from t.C already:

if !t.Stop() {
	<-t.C
}

This cannot be done concurrent to other receives from the Timer's channel or other calls to the Timer's Stop method.

For a timer created with AfterFunc(d, f), if t.Stop returns false, then the timer has already expired and the function f has been started in its own goroutine; Stop does not wait for f to complete before returning. If the caller needs to know whether f is completed, it must coordinate with f explicitly.

type Weekday

A Weekday specifies a day of the week (Sunday = 0, ...).

type Weekday int

const (
    Sunday Weekday = iota
    Monday
    Tuesday
    Wednesday
    Thursday
    Friday
    Saturday
)

func (Weekday) String

func (d Weekday) String() string

String returns the English name of the day ("Sunday", "Monday", ...).

Subdirectories