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How to calculate the the interval between 2 unix timestamps in php WITHOUT dividing by 86400 (60*60*24)

Answer 1

A:

Dividing by 86400 is reliable and easy. I don't know any special functions and i don't see a reason for them to exist.

Māris Kiseļovs 2010-09-20 13:07:02

In 5.3, new DateTime($t1)->diff(new DateTime($t2)) is easy and clear. But the OP asked for pre 5.3 a solution.

Colin Fine 2010-09-20 13:12:36

what Daniel said

fatjoze 2010-09-20 13:21:16

Which is why one should save timestamps in UTC.

You 2010-09-20 13:25:16

dude im using STRTOTIME to get these timestamps, isn't that UTC

fatjoze 2010-09-20 13:48:20

STRTOTIME has nothing to do with timezones.

mizipzor 2010-09-20 14:00:04

@mizipzor: strtotime has very much to do with timezones - it converts a human readable date to a timestamp, and it has to use a specific timezone to interpret the date.

Michael Borgwardt 2010-09-20 14:12:08

Answer 2

+2 A:

A correct Unix (POSIX) timestamp is in UTC, so you're starting out with values that are already wrong. You're facing an uphill battle, since APIs will generally assume that timestamps are in UTC. It would be best to fix this, after which the simple division would actually give the correct result.

Michael Borgwardt 2010-09-20 13:29:38

i have no idea if its UTC, im just runing STRTOTIME, so if you're saying strtotime generates a GMT instead of UNIX (POSIX) then yea guess i'm screwed. you seem knowledgable, i assume you're sayin there's no reliable way other than the 5.3+ methods???

fatjoze 2010-09-20 13:35:30

@fatjoze: To be exact, it's wrong to say that strtotime generates a timestamp in a specific timezone. It always generates UTC, the question is what timezone it uses to interpret the human-readable date parameter. And it looks like that's incorrect in your case because the timestamps you list do not correspond to 00:00 in either UTC or Auckland time. You can set the default timezone via date_default_timezone_set()

Michael Borgwardt 2010-09-20 13:54:32

@fatjoze: At second glance, your timestamps seem to correspond to 00:00 in Sydney - is it possible that that's where your servers are and what they're configured to use as default timezone?

Michael Borgwardt 2010-09-20 13:57:48

thank you very very much Michael, very knowledgeable support, my timestamps SHOULD be Auckland New Zealand, i have used set_default_date_timezone (forgot the actual name) to set my timezone accordingly, so yea not sure why its showing sydney time. Do you live in sydney? lol. none the less I followed Gumbos solution to divide both numbers by 86400 then floor each, THEN subtract. It appears to work so far..

fatjoze 2010-09-20 14:58:39

Answer 3

+2 A:

Check out this link -

http://www.if-not-true-then-false.com/2010/php-calculate-real-differences-between-two-dates-or-timestamps/

Alpesh 2010-09-20 13:36:47

`date_diff` is not available before PHP 5.3.

Daniel Vandersluis 2010-09-20 13:37:43

great stuff, not available pre 5.3 but oh well, still nice to have as reference!

fatjoze 2010-09-20 15:00:53

Answer 4

+1 A:

Calculate the number of full days for both timestamps before calculating the difference:

floor(1284985360 / 86400) - floor(1233925200 / 86400)

The your result is always an integer.

And since you’re using strtotime to get these timestamps, specify the time 00:00:00+0000 to always get a multiple of 86400:

strtotime($str.' 00:00:00+0000')

Gumbo 2010-09-20 13:54:24

Only sensible solution so far. Good job downvoter.

Mchl 2010-09-20 14:23:45

Answer 5

A:

Gumbo good solution, it works, thankyou!!

fatjoez 2010-09-20 14:42:01

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How to calculate the the interval between 2 unix timestamps in php WITHOUT dividing by 86400 (606024)

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