RE: [PHP] Date addition problem

> -----Original Message----- > From: Adrian Bruce [mailto:abruce@stvincent.ac.uk] > Sent: 29 March 2006 13:52 > > I am having an unusual problem when trying to calculate dates > in advance > from a start date. the code below shows a loop where by on > each run an > increasing number of weeks is added to the start date, this works as > expected up untill the 8th time where for some reason it produces > 01-11-05 instead of 02-11-05. I am at a loss as to why this would > happen when it works perfectly for all the other dates. where am i > going wrong? > > [snip] > > <?php > echo"<h1> date test</h1>"; > $start = "05-09-07"; > $start = explode('-',$start); > $startmk = mktime(0,0,0,$start[1],$start[2],$start[0]); > $startdate = date('d-m-y',$startmk); > > for($i=0;$i<10;$i++){ > $nextdate = date('d-m-y',$startmk + ($i*604800)); > echo"<h1>$i: $startdate -- -- --$nextdate</h1>"; > } > ?> You're not allowing for DST shifts. 02-11-05 is after the clocks go back an hour, so instead of getting 00:00 on 02-11-05 you're getting 11:00 on 01-11-05. I always suggest working with the *other* 12 o'clock when calculating purely date offsets -- 12:00 may still shift to 11:00 or 13:00, but this will not affect the date! Cheers! Mike ------------------------------------------------------------------------ ---------------- Mike Ford, Electronic Information Services Adviser, Learning Support Services, JG125, The Library, James Graham Building, Headingley Campus, Beckett Park, LEEDS, LS6 3QS, United Kingdom Tel: +44 113 283 2600 extn 4730 Fax: +44 113 283 3211 To view the terms under which this email is distributed, please go to http://disclaimer.leedsmet.ac.uk/email.htm