Comments on: Covert UNIX Epoch dates in Microsoft Excel – Including Timezone Examples

By: Chris

Chris — Mon, 05 Apr 2010 16:12:43 +0000

I’ve recently been working in importing datetimes from Excel into an SQL database using PHP. The library I was using to read the Excel sheet is called phpexcel. What I found was that there are just too many formats that a date can be stored in (dd/mm/yy, mm/dd/yy, yyyy-mm-dd) for strtotime to be able to handle. This lead me to import the Excel datetime values and convert to Unix values using the following function:

function time_format($datetime,$tzoffset){

if(is_numeric($datetime)){

if(date(‘I’)){

$datetime = (-25569-($tzoffset+1)/24+$datetime)*24*60*60;

}else{

$datetime = (-25569-$tzoffset/24+$datetime)*24*60*60;

}

$datetime = date(‘Y-m-d H:i:s’,$datetime);

return $datetime;

}

The variable $tzoffset is the timezone offset.

The date(‘I’) part checks if we are in daylight savings time or not.

I know this isn’t entirely relevant but hopefully it will be of use to someone.

By: EricPell

EricPell — Wed, 17 Mar 2010 15:05:44 +0000

GMT -03:00 would be:

=((A1-10800)/86400)+25569

By: Dante

Dante — Wed, 17 Mar 2010 14:49:57 +0000

GMT -03:00.. help?

By: David Morel

David Morel — Mon, 11 Jan 2010 15:12:16 +0000

Actually, on my version of excel (mac 2008) the dates are off by 3 years. The correct formula seems to be
=(((A2+3600)/86400)+24107)

this is for GMT+1 of course

By: EricPell

EricPell — Tue, 11 Aug 2009 14:55:55 +0000

GMT + 8 would be: =((A1-28800)/86400)-25569

By: EricPell

EricPell — Tue, 11 Aug 2009 14:54:56 +0000

Daylight savings time may be tricky. You’d need some logic in Excel to detect what the date is and then calculate if you need to alter the formula. I’ll try to look into that some more.

By: Luis Blanco

Luis Blanco — Wed, 05 Aug 2009 16:38:36 +0000

How about The DayLight Time?

By: nicker.par

nicker.par — Mon, 20 Jul 2009 07:24:30 +0000

How about for singapore

GMT +8:00 ??? I M in Dizzy in calculating.

Thanks and rgds