[REBOL] Re: How to scale Date-Time properly in REBOL?
From: brett:codeconscious at: 14-Jan-2002 19:26
Hi Jason,
> what do you suggest?
You're probably not going to like this :)
Ask [feedback--rebol--com].
*ducks*
Other than that I've include just a few miscellanous functions I've used
(not very often) just to feel like I contributed something of even small
use:
;
; Datetimes
;
subtract-datetimes: function [
"Subract one date from another returning time between them."
a [date!]
b [date!]
] [delta-days delta-hhmmss a-hhmmss b-hhmmss] [
delta-days: subtract a/date b/date
a-hhmmss: either a/time [a/time] [00:00:00]
b-hhmmss: either b/time [b/time] [00:00:00]
return add (multiply 24:00:00 delta-days) (subtract a-hhmmss b-hhmmss)
]
;
; Dates
;
add-months: function [
"Add months to a date."
date [date!]
months [integer!]
] [result-date delta-years delta-months] [
delta-years: to-integer divide months 12
delta-months: remainder months 12
if lesser? delta-months 0 [
delta-years: subtract delta-years 1
delta-months: add delta-months 12
]
result-date: date
result-date/year: add result-date/year delta-years
result-date/month: add result-date/month delta-months
return result-date
]
first-day?: func [
"First day of the month."
date "Specifies a month using an sample date." [date!]
][
to-date reduce[1 date/month date/year]
]
days-in-month?: func [
"Number of days in the month."
date "Specifies a month using an sample date." [date!]
][
subtract to-date reduce[1 date/month + 1 date/year] first-day? date
]
last-day: last-day?: func [
"Last day of the month."
date "Specifies a month using an sample date." [date!]
][
to-date reduce [ days-in-month? date date/month date/year]
]
Cheers,
Brett.
