subtract 1 day

[meltedown]

I can't see what I'm doing wrong. I'm subtracting 60*60*24 from a unix
time stamp and the result is 23 hours earlier, not 24.
Start with a unix time stamp:

$unixtime=11440 18006;

convert it to a date:
$date=getdate($ unixtime);
date Array
(
[seconds] => 46
[minutes] => 46
[hours] => 17
[mday] => 2
[wday] => 0
[mon] => 4
[year] => 2006
[yday] => 91
[weekday] => Sunday
[month] => April
[0] => 1144018006
)
date


subtract 1 day:
$gobackseconds= 60*60*24 ;
$unixtime2=$uni xtime-$gobackseconds;

and see what time it is:
$date2=getdate( $unixtime2);


date2 Array
(
[seconds] => 46
[minutes] => 46
[hours] => 16
[mday] => 1
[wday] => 6
[mon] => 4
[year] => 2006
[yday] => 90
[weekday] => Saturday
[month] => April
[0] => 1143931606
)
date2

Notice that in the first date, there are 17 hours, and in the second
date there are 16 hours. Arrrrrrg. What is the problem ?

[Andy Jeffries]

Re: subtract 1 day

On Mon, 03 Apr 2006 08:06:55 +0000, meltedown wrote:[color=blue]
> I can't see what I'm doing wrong. I'm subtracting 60*60*24 from a unix
> time stamp and the result is 23 hours earlier, not 24. Start with a unix
> time stamp:[/color]

Try doing this instead:

$unixtime2 = strtotime("-1 day", $unixtime);

I couldn't see what you were doing wrong in your code from a quick glance,
but the above way is easier to read anyway.

Cheers,


Andy

--
Andy Jeffries MBCS CITP ZCE | gPHPEdit Lead Developer
http://www.gphpedit.org | PHP editor for Gnome 2
http://www.andyjeffries.co.uk | Personal site and photos

[meltedown]

Re: subtract 1 day

Andy Jeffries wrote:[color=blue]
> On Mon, 03 Apr 2006 08:06:55 +0000, meltedown wrote:[color=green]
>> I can't see what I'm doing wrong. I'm subtracting 60*60*24 from a unix
>> time stamp and the result is 23 hours earlier, not 24. Start with a unix
>> time stamp:[/color]
>
> Try doing this instead:
>
> $unixtime2 = strtotime("-1 day", $unixtime);
>
> I couldn't see what you were doing wrong in your code from a quick glance,
> but the above way is easier to read anyway.
>
> Cheers,
>
>
> Andy
>[/color]
Thanks that really helped a lot, five minutes to fix what I've been
banging my head against all night. Funny thing is that code worked fine
for a year and it still works for most dates but it hit that one date
and didn't work right.

[Andy Jeffries]

Re: subtract 1 day

On Mon, 03 Apr 2006 08:59:19 +0000, meltedown wrote:[color=blue][color=green]
>> Try doing this instead:
>>
>> $unixtime2 = strtotime("-1 day", $unixtime);
>>
>> I couldn't see what you were doing wrong in your code from a quick
>> glance, but the above way is easier to read anyway.
>>[/color]
> Thanks that really helped a lot, five minutes to fix what I've been
> banging my head against all night.[/color]

It's always the way with coding.... Glad I could help.
[color=blue]
> Funny thing is that code worked fine
> for a year and it still works for most dates but it hit that one date and
> didn't work right.[/color]

It's very odd. I've had another quick glance at your code and still can't
see anything obviously wrong. Never mind, you've got a solution now.

Cheers,


Andy

--
Andy Jeffries MBCS CITP ZCE | gPHPEdit Lead Developer
http://www.gphpedit.org | PHP editor for Gnome 2
http://www.andyjeffries.co.uk | Personal site and photos

[Kimmo Laine]

Re: subtract 1 day

"meltedown" <groups2@reenie .org> wrote in message
news:Gt5Yf.2028 83$G_2.26129@fe 08.news.easynew s.com...[color=blue]
> Andy Jeffries wrote:[color=green]
>> On Mon, 03 Apr 2006 08:06:55 +0000, meltedown wrote:[color=darkred]
>>> I can't see what I'm doing wrong. I'm subtracting 60*60*24 from a unix
>>> time stamp and the result is 23 hours earlier, not 24. Start with a unix
>>> time stamp:[/color]
>>
>> Try doing this instead:
>>
>> $unixtime2 = strtotime("-1 day", $unixtime);
>>
>> I couldn't see what you were doing wrong in your code from a quick
>> glance,
>> but the above way is easier to read anyway.
>>
>> Cheers,
>>
>>
>> Andy
>>[/color]
> Thanks that really helped a lot, five minutes to fix what I've been
> banging my head against all night. Funny thing is that code worked fine
> for a year and it still works for most dates but it hit that one date and
> didn't work right.[/color]

I had the same effect when clocks were turned +1 hour to daylight saving
time on March 26th here in Finland. I had two dates of which one was in
normal time and another that was in daylight saving time and I kept
wondering why the difference between them is was 5 days and 23 hours or
something like that, until the whole daylight saving thing finally dawned to
me. I fixed it by using GMT times which are not affected by DST.

--
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