use of date n time functions

blackgoat has asked for the wisdom of the Perl Monks concerning the following question:

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Re: use of date n time functions by CountZero (Bishop) on Mar 08, 2010 at 07:17 UTC
Use `my ($weekday, $month, $day, $hours, $minutes, $seconds, $whatever) = s +plit /[_:]/, 'mon_jan_01_16:00:33_t23.96-d568'` [download] to get the components of your string (having made a guess at what these components are, of course). Then have a look at Time::Local which can transform the above components (hint: the name of the month must still be transformed into its sequence number) of your date-time string into the number of seconds since the epoch. It is then very easy to sort according to that number. One difficulty you will have to surmount is the missing year in your date-time string. Perhaps you can assume it is always the present year? CountZero A program should be light and agile, its subroutines connected like a string of pearls. The spirit and intent of the program should be retained throughout. There should be neither too little or too much, neither needless loops nor useless variables, neither lack of structure nor overwhelming rigidity." - The Tao of Programming, 4.1 - Geoffrey James	[reply] [d/l]
Re: use of date n time functions by ZlR (Chaplain) on Mar 08, 2010 at 10:03 UTC
Or you could parse out the dates with a regex, then use the Date::Calc bazooka to compare theses dates and find the most recent one. The advantage of this being that you don't have to take into acount tricky dates pitfalls like leap years and so forth, as Date::Calc does that for you.	[reply]
Re^2: use of date n time functions by blackgoat (Acolyte) on Mar 09, 2010 at 05:16 UTC
Could you pls give me a sample showing how to use Date::Calc to compare dates??	[reply]
Re^3: use of date n time functions by ZlR (Chaplain) on Mar 10, 2010 at 11:18 UTC
It's all in the Date::Calc help page : look at the recipes For instance : `use Date::Calc qw( Delta_Days ); if (Delta_Days($year1,$month1,$day1, $year2,$month2,$day2) > 0)` [download] There's also examples about : How do I compare two dates with times? , which might be just what you need.	[reply] [d/l]
Re: use of date n time functions by ikegami (Patriarch) on Mar 08, 2010 at 07:18 UTC
Parse out the date with a regex, pass the dates to Time::Local's `timegm`, find the biggest of the returned numbers.	[reply] [d/l]
Re: use of date n time functions by Anonymous Monk on Mar 08, 2010 at 07:04 UTC
What is the name of that format?	[reply]
Re^2: use of date n time functions by blackgoat (Acolyte) on Mar 08, 2010 at 07:11 UTC
I do not know of any name of the format, its just how the data resides.	[reply]
Re^3: use of date n time functions by Anonymous Monk on Mar 08, 2010 at 07:17 UTC
I do not know of any name of the format, its just how the data resides. Then how are you supposed to make sense of the data?	[reply]
Re^4: use of date n time functions by jeffreyray (Sexton) on Mar 08, 2010 at 20:01 UTC
Re^5: use of date n time functions by Anonymous Monk on Mar 08, 2010 at 22:04 UTC
Re: use of date n time functions by thinc (Novice) on Mar 09, 2010 at 04:49 UTC
> mon_jan_01_16:00:33_t23.96-d568 `year - unknown (2018,2007,2001,1996? All these years have Jan 1st tha +t falls on a monday) month - January day - 01 hour - 16 minute - 00 second - 33` [download] what do the "t23.96" and the "d568" represent?	[reply] [d/l]
Re^2: use of date n time functions by blackgoat (Acolyte) on Mar 09, 2010 at 05:20 UTC
Pls assume the year to be the current year. I used mon_jan_01 just as an arbitrary example to show format of the data. "t23.96" and "d568" are also just trivial parts of the expression to be matched through regex, pls ignore it!	[reply]