Standard library

std/time

Time: a monotonic clock for measuring, the wall clock and calendar dates.

let start = time.now()
...
println("took", time.formatDuration(time.since(start)))
let d = time.local(time.unixNanos())
println(d.format("%Y-%m-%d %H:%M"))

Constants: nanosecond, microsecond, millisecond, second, minute, hour

Types: struct Date, struct ParseError

Functions: sleep, now, since, unixNanos, unix, formatDuration, dayName, monthName, at, utc, local, date, parseIso

Constants

nanosecond, microsecond, millisecond, second, minute, hour

pub const nanosecond = 1
pub const microsecond = 1000
pub const millisecond = 1000000
pub const second = 1000000000
pub const minute = 60000000000
pub const hour = 3600000000000

Durations are integer nanoseconds.

Types

struct Date

pub copy struct Date {
    pub year: int
    // 1 to 12
    pub month: int
    // 1 to 31
    pub day: int
    pub hour: int
    pub minute: int
    pub second: int
    pub nanosecond: int
    // seconds east of UTC (+08:00 is 28800)
    pub offset: int = 0
}

A calendar date and time of day, at some offset from UTC.

Date.unixNanos

pub fn unixNanos(self) -> int

The moment this is, as nanoseconds since 1970 (see unixNanos).

Date.weekday

pub fn weekday(self) -> int

0 is Sunday.

Date.yearDay

pub fn yearDay(self) -> int

1 to 366.

Date.iso

pub fn iso(self) -> String

RFC 3339: "2026-11-06T14:41:31Z", "2026-11-06T14:41:31.592+08:00".

Date.format

pub fn format(self, layout: str) -> String

Formats with strftime-style directives:

%Y year   %m month   %d day     %H hour   %M minute   %S second
%L milliseconds   %f microseconds   %N nanoseconds
%z +0800   %Z +08:00 (Z for UTC)   %a Mon   %A Monday   %b Jan   %B January
%j day of the year   %e day without zero padding   %%

struct ParseError

pub struct ParseError {
    pub msg: String
}

Why parseIso could not read a date.

ParseError.message

pub fn message(self) -> String

The message, which quotes the input.

Functions

sleep

pub fn sleep(d: int)

Parks the goroutine; other goroutines keep running on its thread. Returns early when the task is cancelled (see task.cancelled).

now

pub fn now() -> int

Monotonic clock in nanoseconds, for measuring; not related to the date.

since

pub fn since(start: int) -> int

Nanoseconds since start, a value of now().

unixNanos

pub fn unixNanos() -> int

The wall clock: nanoseconds since 1970-01-01 00:00 UTC.

unix

pub fn unix() -> int

Seconds since 1970-01-01 00:00 UTC.

formatDuration

pub fn formatDuration(d: int) -> String

"1.5s", "250ms", "3µs", "2h5m0s".

dayName

pub fn dayName(weekday: int) -> str

0 is Sunday.

monthName

pub fn monthName(month: int) -> str

1 is January.

at

pub fn at(ns: int, offset: int) -> Date

The date ns nanoseconds after 1970 is, at offset seconds east of UTC.

utc

pub fn utc(ns: int) -> Date

The date in UTC.

local

pub fn local(ns: int) -> Date

The date in the local time zone.

date

pub fn date(year: int, month: int, day: int, hour: int, minute: int, sec: int) -> Date

A date in UTC.

parseIso

pub fn parseIso(s: str) -> Date ! ParseError

Reads an RFC 3339 date: "2026-11-06T14:41:31Z", "2026-11-06 14:41:31.5+08:00".