date comparison (the three ghosts)

just a quickie...

I need to calculate if a date is either before an events start date (future), after the events end date (past), or between the two (present).

All dates are in the dd/mm/yyyy format.

The only thing I can think of is pulling each date apart and comparing each bit. Surely there must be an easier way.

Cheers for fears.

Are your start date and end dates in the same format:

dd/mm/yyyy



Mickalo

It's partically impossible to do any type of numerical date calculation when you have a date/time formatted like you have now. what you need to do is get the date into a workable format: YYYYMMDD. Then you can do you calculations. Example:
========================
Start Date: 20010101
End Date: 20010301
Todays Date: 20010207
========================
Todays Date is greater then the Start Date and less then the End date, if you do a numerical comparsion.

By treating the dates now as a numerical value. If you store your dates like this, then if you need to display the dates for some reason and you wante to display them as DD-MM-YYYY you will have to manipulate the dates somewhat in the same manner you would do to convert the dates to a numerical value. It involves quiet a bit of substitions substr()

A suggestion. If you need to store dates and need to use this dates for calculations, store your dates in two formats. One for your normal display desired and the same one in a numerical format. Then you can pull either date for what ever you need to do. Another method, is using UN*X time() for date/time calculations. Which is exact to the second!

Mickalo

[Edited by mickalo on 02-08-2001 at 06:37 AM]

Where theres time to burn theres a way...

use Time::Local;
$time_1=timegm(0,0,0, split(/\//, $firstime_var));
$time_2=timegm(0,0,0, split(/\//, $secondtime_var));
$time_3=timegm(0,0,0, split(/\//, $thirdtime_var));

gives the seconds from 1970.

oakish

Cheers guys.

I now have it working.
Split the date from dd/mm/yyyy and then stick it back together as yyymmdd. From here the comparisons where dead easy.

Thanks for the help mickalo; I had forgotten that you could compare dates in the yyyymmdd format.

Somebody should really write a module for date and time manipulation and comparisons.

A quick method to convert your date: DD/MM/YYYY
Just do something like this:


Now the $formate_date equals: 20010208

Mickalo

[Edited by mickalo on 02-08-2001 at 07:43 AM]

I must be bored:



There are those that believe that minimum legibility == maximum job security.