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v/vlib/time/unix.v

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// Copyright (c) 2019-2023 Alexander Medvednikov. All rights reserved.
// Use of this source code is governed by an MIT license
// that can be found in the LICENSE file.
module time
// unix returns a time struct from an Unix timestamp (number of seconds since 1970-01-01)
pub fn unix(abs i64) Time {
// Split into day and time
mut day_offset := abs / seconds_per_day
if abs % seconds_per_day < 0 {
// Compensate for round towards zero on integers as we want floored instead
day_offset--
}
year, month, day := calculate_date_from_offset(day_offset)
hr, min, sec := calculate_time_from_offset(abs % seconds_per_day)
return Time{
year: year
month: month
day: day
hour: hr
minute: min
second: sec
unix: abs
}
}
// unix2 returns a Time struct, given an Unix timestamp in seconds, and a microsecond value
[deprecated: 'use unix_microsecond(unix_ts, us) instead']
[deprecated_after: '2023-09-05']
pub fn unix2(abs i64, microsecond int) Time {
return unix_nanosecond(abs, microsecond * 1000)
}
// unix_microsecond returns a Time struct, given an Unix timestamp in seconds, and a microsecond value
pub fn unix_microsecond(abs i64, microsecond int) Time {
return unix_nanosecond(abs, microsecond * 1000)
}
// unix_nanosecond returns a Time struct, given an Unix timestamp in seconds, and a nanosecond value
pub fn unix_nanosecond(abs i64, nanosecond int) Time {
// Split into day and time
mut day_offset := abs / seconds_per_day
if abs % seconds_per_day < 0 {
// Compensate for round towards zero on integers as we want floored instead
day_offset--
}
year, month, day := calculate_date_from_offset(day_offset)
hr, min, sec := calculate_time_from_offset(abs % seconds_per_day)
return Time{
year: year
month: month
day: day
hour: hr
minute: min
second: sec
nanosecond: nanosecond
unix: abs
}
}
fn calculate_date_from_offset(day_offset_ i64) (int, int, int) {
mut day_offset := day_offset_
// source: http://howardhinnant.github.io/date_algorithms.html#civil_from_days
// shift from 1970-01-01 to 0000-03-01
day_offset += 719468 // int(days_per_400_years * 1970 / 400 - (28+31))
mut era := 0
if day_offset >= 0 {
era = int(day_offset / days_per_400_years)
} else {
era = int((day_offset - days_per_400_years - 1) / days_per_400_years)
}
// doe(day of era) [0, 146096]
doe := day_offset - era * days_per_400_years
// yoe(year of era) [0, 399]
yoe := (doe - doe / (days_per_4_years - 1) + doe / days_per_100_years - doe / (days_per_400_years - 1)) / days_in_year
// year number
mut y := int(yoe + era * 400)
// doy (day of year), with year beginning Mar 1 [0, 365]
doy := doe - (days_in_year * yoe + yoe / 4 - yoe / 100)
mp := (5 * doy + 2) / 153
d := int(doy - (153 * mp + 2) / 5 + 1)
mut m := int(mp)
if mp < 10 {
m += 3
} else {
m -= 9
}
if m <= 2 {
y += 1
}
return y, m, d
}
fn calculate_time_from_offset(second_offset_ i64) (int, int, int) {
mut second_offset := second_offset_
if second_offset < 0 {
second_offset += seconds_per_day
}
hour_ := second_offset / seconds_per_hour
second_offset %= seconds_per_hour
min := second_offset / seconds_per_minute
second_offset %= seconds_per_minute
return int(hour_), int(min), int(second_offset)
}