3c: Urbit Time • Reference • developers.urbit.org

`++year`

Date to @da

Accept a parsed date of form [[a=? y=@ud] m=@ud t=tarp] and produce its @da representation.

Accepts

det is a date

Produces

A @da.

Source

++  year
  |=  det=date
  ^-  @da
  =+  ^=  yer
      ?:  a.det
        (add 292.277.024.400 y.det)
      (sub 292.277.024.400 (dec y.det))
  =+  day=(yawn yer m.det d.t.det)
  (yule day h.t.det m.t.det s.t.det f.t.det)

Examples

> (year [[a=%.y y=2.014] m=8 t=[d=4 h=20 m=4 s=57 f=~[0xd940]]])
~2014.8.4..20.04.57..d940

`++yore`

Date from atomic date

Produces a date from a @da.

Accepts

now is a time atom, @da.

Produces

A date.

Source

++  yore
  |=  now=@da
  ^-  date
  =+  rip=(yell now)
  =+  ger=(yall d.rip)
  :-  ?:  (gth y.ger 292.277.024.400)
        [a=& y=(sub y.ger 292.277.024.400)]
      [a=| y=+((sub 292.277.024.400 y.ger))]
  [m.ger d.ger h.rip m.rip s.rip f.rip]

Examples

> (yore ~2014.6.6..21.09.15..0a16)
[[a=%.y y=2.014] m=6 t=[d=6 h=21 m=9 s=15 f=~[0xa16]]]

`++yell`

Tarp from atomic date

Produce a $tarp time format from a@da.

Accepts

now is a @da.

Produces

A tarp.

Source

++  yell
  |=  now=@d
  ^-  tarp
  =+  sec=(rsh 6 now)
  =+  ^=  fan
      =+  [muc=4 raw=(end 6 now)]
      |-  ^-  (list @ux)
      ?:  |(=(0 raw) =(0 muc))
        ~
      =>  .(muc (dec muc))
      [(cut 4 [muc 1] raw) $(raw (end [4 muc] raw))]
  =+  day=(div sec day:yo)
  =>  .(sec (mod sec day:yo))
  =+  hor=(div sec hor:yo)
  =>  .(sec (mod sec hor:yo))
  =+  mit=(div sec mit:yo)
  =>  .(sec (mod sec mit:yo))
  [day hor mit sec fan]

Examples

> (yell ~2014.3.20..05.42.53..7456)
[d=106.751.991.820.094 h=5 m=42 s=53 f=~[0x7456]]

> (yell ~2014.6.9..19.09.40..8b66)
[d=106.751.991.820.175 h=19 m=9 s=40 f=~[0x8b66]]

> (yell ~1776.7.4)
[d=106.751.991.733.273 h=0 m=0 s=0 f=~]

`++yule`

Daily time to time atom

Accepts a $tarp, a parsed daily time, and produces a @da.

Accepts

rip is a tarp.

Produces

A time atom, @da.

Source

++  yule
  |=  rip=tarp
  ^-  @d
  =+  ^=  sec  ;:  add
                 (mul d.rip day:yo)
                 (mul h.rip hor:yo)
                 (mul m.rip mit:yo)
                 s.rip
               ==
  =+  ^=  fac  =+  muc=4
               |-  ^-  @
               ?~  f.rip
                 0
               =>  .(muc (dec muc))
               (add (lsh [4 muc] i.f.rip) $(f.rip t.f.rip))
  (con (lsh 6 sec) fac)

Examples

> =murica (yell ~1776.7.4)

> murica
[d=106.751.991.733.273 h=0 m=0 s=0 f=~]

> (yule murica)
0x8000000b62aaf5800000000000000000

> `@da`(yule murica)
~1776.7.4

> `@da`(yule (yell ~2014.3.20..05.42.53..7456))
~2014.3.20..05.42.53..7456

> `tarp`[31 12 30 0 ~]
[d=31 h=12 m=30 s=0 f=~]

> `@dr`(yule `tarp`[31 12 30 0 ~])
~d31.h12.m30

`++yall`

Time since beginning of time

Produce the date tuple of [y=@ud m=@ud d=@ud] of the year, month, and day from a number of days from the beginning of the Gregorian calendar.

Accepts

day is a @ud.

Produces

A cell of unsigned decimals.

Source

++  yall
  |=  day=@ud
  ^-  [y=@ud m=@ud d=@ud]
  =+  [era=0 cet=0 lep=*?]
  =>  .(era (div day era:yo), day (mod day era:yo))
  =>  ^+  .
      ?:  (lth day +(cet:yo))
        .(lep &, cet 0)
      =>  .(lep |, cet 1, day (sub day +(cet:yo)))
      .(cet (add cet (div day cet:yo)), day (mod day cet:yo))
  =+  yer=(add (mul 400 era) (mul 100 cet))
  |-  ^-  [y=@ud m=@ud d=@ud]
  =+  dis=?:(lep 366 365)
  ?.  (lth day dis)
    =+  ner=+(yer)
    $(yer ner, day (sub day dis), lep =(0 (end [0 2] ner)))
  |-  ^-  [y=@ud m=@ud d=@ud]
  =+  [mot=0 cah=?:(lep moy:yo moh:yo)]
  |-  ^-  [y=@ud m=@ud d=@ud]
  =+  zis=(snag mot cah)
  ?:  (lth day zis)
    [yer +(mot) +(day)]
  $(mot +(mot), day (sub day zis))

Examples

> (yall 198)
[y=0 m=7 d=17]

> (yall 90.398)
[y=247 m=7 d=3]

> (yall 0)
[y=0 m=1 d=1]

`++yawn`

Days since beginning of time

Inverse of yall, computes number of days A.D. from y/m/d date as the tuple [yer=@ud mot=@ud day=@ud].

Accepts

yer is an unsigned decimal.

mon is an unsigned decimal.

day is an unsigned decimal.

Produces

An unsigned decimal.

Source

++  yawn
  |=  [yer=@ud mot=@ud day=@ud]
  ^-  @ud
  =>  .(mot (dec mot), day (dec day))
  =>  ^+  .
      %=    .
          day
        =+  cah=?:((yelp yer) moy:yo moh:yo)
        |-  ^-  @ud
        ?:  =(0 mot)
          day
        $(mot (dec mot), cah (slag 1 cah), day (add day (snag 0 cah)))
      ==
  |-  ^-  @ud
  ?.  =(0 (mod yer 4))
    =+  ney=(dec yer)
    $(yer ney, day (add day ?:((yelp ney) 366 365)))
  ?.  =(0 (mod yer 100))
    =+  nef=(sub yer 4)
    $(yer nef, day (add day ?:((yelp nef) 1.461 1.460)))
  ?.  =(0 (mod yer 400))
    =+  nec=(sub yer 100)
    $(yer nec, day (add day ?:((yelp nec) 36.525 36.524)))
  (add day (mul (div yer 400) (add 1 (mul 4 36.524))))

Examples

> (yawn 2.018 7 4)
737.244

> (yawn 1.776 7 4)
648.856

> (yawn 1.990 10 11)
727.116

`++yelp`

Leap year?

Determines whether a year is a leap year. Produces a flag.

Accepts

yer is an unsigned decimal.

Produces

A flag.

Source

++  yelp
  |=  yer=@ud  ^-  ?
  &(=(0 (mod yer 4)) |(!=(0 (mod yer 100)) =(0 (mod yer 400))))

Examples

> (yelp 2.014)
%.n

> (yelp 2.008)
%.y

> (yelp 0)
%.y

> (yelp 14.011)
%.n

`++yo`

Time constants core

Core whose arms contain constants for interacting with earth time.

Source

++  yo

`++cet:yo`

Days in a century

Derived by multiplying the number of days in a year (365) by the number of years in a century (100), then adding the number days from leap-years in a century (24).

Produces

An atom.

Source

++  cet  36.524

Examples

> cet:yo
36.524

> (add 365 cet:yo)
36.889

> (sub (add 24 (mul 100 365)) cet:yo)
0

`++day:yo`

Seconds in day

The number of seconds in a day.

Produces

An atom.

Source

++  day  86.400

Examples

> day:yo
86.400

> (add 60 day:yo)
86.460

`++era:yo`

Leap-year period

The number of days in a 400-year period, arrived at by multiplying cet by four and adding one. This is done because every 400 years, there is a leap-year where there would otherwise not be.

Produces

An atom.

Source

++  era  146.097

Examples

> era:yo
146.097

> (sub era:yo (mul 4 cet:yo))
1

Discussion

A year is a leap-year if:

it's divisible by 4;
unless it's divisible by 100;
or if it's divisible by 400.

`++hor:yo`

Seconds in hour

The number of seconds in an hour. Derived by multiplying the number of seconds in a minute by the minutes in an hour.

Produces

An atom.

Source

++  hor  3.600

Examples

> hor:yo
3.600

> (div hor:yo 60)
60

`++jes:yo`

Maximum 64-bit timestamp

This is the number of days (starting from 1970) that can be represented in a 64-bit timestamp. Derived by multiplying era:yo by 730,692,561.

Produces

An atom.

Source

++  jes  106.751.991.084.417

Examples

> jes:yo
106.751.991.084.417

Discussion

The date is December 4, 292,277,026,596.

`++mit:yo`

Seconds in minute

The number of seconds in a minute.

Produces

An atom.

Source

++  mit  60

Examples

> mit:yo
60

`++moh:yo`

Days in month

The days in each month of the Gregorian common year. A list of unsigned decimal atoms (Either 28, 30, or 31) denoting the number of days in the month at the year at that index.

Produces

A list of @ud

Source

++  moh  `(list @ud)`[31 28 31 30 31 30 31 31 30 31 30 31 ~]

Examples

> moh:yo
~[31 28 31 30 31 30 31 31 30 31 30 31]

> (snag 4 moh:yo)
31

`++moy:yo`

Days in months of leap-year

The days in each month of the Gregorian leap-year. A list of unsigned decimal atoms (Either 29, 30, or 31) denoting the number of days in the month at the leap-year at that index.

Produces

A list of @ud.

Source

++  moy  `(list @ud)`[31 29 31 30 31 30 31 31 30 31 30 31 ~]

Examples

> moy:yo
~[31 29 31 30 31 30 31 31 30 31 30 31]

> (snag 1 moy:yo)
29

`++qad:yo`

Seconds in 4 years

The number of seconds in four years. Derived by adding one second to the number of seconds in four years.

Produces

An atom.

Source

++  qad  126.144.001

Examples

> qad:yo
126.144.001

`++yer:yo`

Seconds in year

The number of seconds in a year. Derived by multiplying the number of seconds in a day by 365.

Produces

An atom.

Source

++  yer  31.536.000

Examples

> yer:yo
31.536.000