JPhrases/DateTime

14B. Date & Time

m0=: 6!:0	System time stamp yyyy mm dd hh mm ss (argument y needed but ignored)
m1=: [:<._3:{.]	hh mm ss part of time stamp
m2=: 1000"_ #. ]	Base-1000 form of y
m3=: (':'"_) _6 _3} ":	Format with ':' between fields
m4=: [:<.3:{.]	yyyy mm dd part of time stamp
m5=: ('/'"_) 4 7} ":	Format with '/' between fields
m6=: [: m3 [: m2 [: m1 m0	Formatted time stamp hh:mm:ss
m7=: [: m5 [: m2 [: m4 m0	Formatted date stamp yyyy/mm/dd
m8=: (':'"_) 2 5} [: ": 1000"_ #. _3: {. [: <. m0	Formatted time stamp hh:mm:ss
m9=: ('/'"_) 4 7} [: ": 1000"_ #. 3: {. [: <. m0	Formatted date stamp yyyy.mm/dd
m10=: 100"_#.100"_|3:{. m0	yymmdd from ccyy mm dd (y neglected)
m11=: 0: ~:/ .= 4 100 400"_ |/ ]	Is y a leap year?
m12=: 28"_ + m11@]	Number of days in February of year y
d13=: 31"_ - 2: | 7: | [	31 - 2 | 7 | x: days in month x, not = 1
d14=: d13`m12@.([=1:)	Number of days in month x of year y
m15=: ('0123456789 '"_ i.[:":[:|. 3: {. 6!:0) { ('0123456789.'"_)	Current date in dd.mm.yy fmt, neglect y
m16=: ((12"_ <: {.),2:) { 'apm'"_	am or pm depending on first atom of y
m17=: ([: m3 m2) , (' '"_ , m16)	Formatted 3-atom time y in 'm' form
m18=: [:":[:(1:|.])100"_|[:m4 m0	Formatted date in mm dd yy form
m19=: '/'"_(]#[:i.#)@(' '"_=])}]	Replace blanks in y by '/'
m20=: m19@m18	Formatted date in mm/dd/yy form
m21=: >:@(365&* + m22)@(-&1601)	# of New Year&#146;s Day, Gregorian year y; m21 1601 is 1
m22=: -/@:<.@(%&4 100 400)"0	# of leap days in y years (Clavian corr.)
m23=: 7&|@m21	Day of week year y begins (0=Sunday)

Number of New Year’s Day for Gregorian years.

   m21 1601 1602 2001
1 366 146098
}}} Number of leap days in{{{ y }}}years

   m22 0 1 4 100 400 2000
0 0 1 24 97 485
}}} Day of week year{{{ y }}}begins (0 is Sunday)

   m23 1900 2000
1 6