mirror of
https://git.FreeBSD.org/ports.git
synced 2024-10-31 21:57:12 +00:00
56 lines
2.4 KiB
Plaintext
56 lines
2.4 KiB
Plaintext
|
This is a set of routines designed to make any common
|
||
|
|
date/time manipulation easy to do. Operations such as
|
||
|
|
comparing two times, calculating a time a given amount of
|
||
|
|
time from another, or parsing international times are all
|
||
|
|
easily done.
|
||
|
|
|
||
|
|
Date::Manip deals only with the Gregorian calendar (the
|
||
|
|
one currently in use). The Julian calendar defined leap
|
||
|
|
years as every 4th year. The Gregorian calendar improved
|
||
|
|
this by making every 100th year NOT a leap year, unless it
|
||
|
|
was also the 400th year. The Gregorian calendar has been
|
||
|
|
extrapolated back to the year 1000 AD and forward to the
|
||
|
|
year 9999 AD. Note that in historical context, the Julian
|
||
|
|
calendar was in use until 1582 when the Gregorian calendar
|
||
|
|
was adopted by the Catholic church. Protestant countries
|
||
|
|
did not accept it until later; Germany and Netherlands in
|
||
|
|
1698, British Empire in 1752, Russia in 1918. Note that
|
||
|
|
the Gregorian calendar is itself imperfect. Each year is
|
||
|
|
on average 26 seconds too long, which means that every
|
||
|
|
3,323 years, a day should be removed from the calendar.
|
||
|
|
No attempt is made to correct for that.
|
||
|
|
|
||
|
|
Date::Manip is therefore not equipped to truly deal with
|
||
|
|
historacle dates, but should be able to perform
|
||
|
|
(virtually) any operation dealing with a modern time and
|
||
|
|
date.
|
||
|
|
|
||
|
|
Among other things, Date::Manip allow you to:
|
||
|
|
|
||
|
|
1. Enter a date and be able to choose any format
|
||
|
|
conveniant
|
||
|
|
|
||
|
|
2. Compare two dates, entered in widely different formats
|
||
|
|
to determine which is earlier
|
||
|
|
|
||
|
|
3. Extract any information you want from ANY date using a
|
||
|
|
format string similar to the Unix date command
|
||
|
|
|
||
|
|
4. Determine the amount of time between two dates
|
||
|
|
|
||
|
|
5. Add a time offset to a date to get a second date (i.e.
|
||
|
|
determine the date 132 days ago or 2 years and 3 months
|
||
|
|
after Jan 2, 1992)
|
||
|
|
|
||
|
|
6. Work with dates with dates using international formats
|
||
|
|
(foreign month names, 12-10-95 referring to October rather than
|
||
|
|
December, etc.).
|
||
|
|
|
||
|
|
Each of these tasks is trivial (one or two lines at most)
|
||
|
|
with this package.
|
||
|
|
|
||
|
|
Although the word date is used extensively here, it is
|
||
|
|
actually somewhat misleading. Date::Manip works with the
|
||
|
|
full date AND time (year, month, day, hour, minute,
|
||
|
|
second).
|