dan/liminix
2
0
Fork 6
Code Activity

unix time to TAI conversion

Browse Source
This commit is contained in:
Daniel Barlow
2025-10-28 21:05:55 +00:00
parent 8049714cdb
commit c3d6ad7ad4
1 changed files with 46 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

57
pkgs/anoia/tai64.fnl
View File

@@ -37,21 +37,31 @@
[3644697600 36] ; 1 Jul 2015
[3692217600 37] ; 1 Jan 2017
]]
(icollect [_ [ts dtai] (ipairs tbl)]
[(+ (- ts 2208988800) dtai) dtai])))
{
:tai
(icollect [_ [ts dtai] (ipairs tbl)]
[(+ (- ts 2208988800) dtai) dtai])
:unix
(icollect [_ [ts dtai] (ipairs tbl)]
[(- ts 2208988800) dtai])
}))
(fn leap-seconds [timestamp]
(fn leap-seconds [timestamp list]
(accumulate [secs 10
_ [epoch leap-seconds] (ipairs leap-seconds-list)
_ [epoch leap-seconds] (ipairs list)
&until (> epoch timestamp)]
leap-seconds))
(fn leap-seconds-tai [tai] (leap-seconds tai leap-seconds-list.tai))
(fn leap-seconds-unix [unix] (leap-seconds unix leap-seconds-list.unix))
(define-tests :leap-seconds
(expect= (leap-seconds 104694412) 12)
(expect= (leap-seconds 23) 10)
(expect= (leap-seconds (+ 3692217600 60)) 37)
(expect= (leap-seconds (+ 10 773020829)) 29)
(expect= (leap-seconds 362793520) 19))
(expect= (leap-seconds-tai 104694412) 12)
(expect= (leap-seconds-tai 23) 10)
(expect= (leap-seconds-tai (+ 3692217600 60)) 37)
(expect= (leap-seconds-tai (+ 10 773020829)) 29)
(expect= (leap-seconds-tai 362793520) 19))
(fn from-timestamp [str]
(if (= (string.sub str 1 1) "@")
@@ -65,7 +75,16 @@
nil))
(fn to-unix [tai]
(values (- tai.s (leap-seconds tai.s)) tai.n))
(values (- tai.s (leap-seconds-tai tai.s)) tai.n))
(fn from-unix [seconds nanos]
(let [s (math.floor seconds)
;; subsecond value may be given as fraction or as a separate
;; param, but not both
n (or nanos (* (- seconds s) 1e9))]
{ :s
(+ s (leap-seconds-unix s))
:n n }))
(define-tests
(expect=
@@ -74,6 +93,22 @@
(let [(s n) (to-unix (from-timestamp "@4000000068e2f0d3257dc09b"))]
(expect= [s n] [1759703214 628998299]))
(let [{ : s : n } (from-unix 1759703214 1e6)]
(expect= [s n] [1759703251 1e6]))
(let [{ : s : n } (from-unix 1759703214.5)]
(expect= [s n] [1759703251 5e8]))
;; check the leap second count is looked up correctly around a
;; boundary
(let [unix (os.time {:year 2016 :month 12 :day 31 :hour 23 :min 59 :sec 58})
tai (from-unix unix)]
(expect= (- tai.s unix) 36))
(let [unix (os.time {:year 2016 :month 12 :day 31 :hour 23 :min 59 :sec 63})
tai (from-unix unix)]
(expect= (- tai.s unix) 37))
)
{ : from-timestamp : to-unix }
{ : from-timestamp : to-unix : from-unix }