Convert UNIX timestamp

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kkaal
Posts: 2
Joined: Thu Dec 06, 2007 11:17 am

Convert UNIX timestamp

Post by kkaal »

Hi,

I have a database which was populated with UNIX timestamps as Integer values.

Can anybody tell me how to convert this to OO formats?

Thanks
Klaus
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probe1
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Posts: 277
Joined: Mon Oct 08, 2007 1:34 am
Location: Chonburi Thailand

Re: Convert UNIX timestamp

Post by probe1 »

Unix timestamp is seconds since 1st January 1970.
So:
divide by number of seconds per day (86400), gives you the number of days since then, add 25569 (which is 1.1.1970 0:00h) in OOo Calc [Tools>Options...>OpenOffice.org Calc>Calculate>start date as 30.12.1899]

Now you can format as you like.
Does this help?
Cheers
Winfried

DateTime2 extension: insert date, time or timestamp, formatted to your needs
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ambparker
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Joined: Mon Oct 28, 2013 7:52 am
Location: USA

Re: Convert UNIX timestamp

Post by ambparker »

This is not something I discovered myself, rather it's something that I'll need every now and then when doing extemporary reports of UNIX-timestamped data. The problem is: you have a time series of data in a spreadsheet, and the time is expressed as UNIX timestamps (seconds since the epoch, 1970-01-01 00:00:00 UTC, and not taking into account leap seconds): how can you convert those timestamps in a readable date like, e.g., "01/07/2012 01:00:00"?

I found a very useful suggestion in the OpenOffice community forum. As it seems, OpenOffice's "day 0" is December 12th, 1899; that implies that January 1st, 1970 is day 25569 for OpenOffice. Now, if you divide a UNIX timestamp by 86400 (the number of seconds in a normal day), that will give you the number of days between the epoch and that timestamp (and some decimal, that you can use to calculate the time of day). And if you sum that number with 25569, you have an OpenOffice day for that timestamp.

Alright, let's put all the pieces together: let's say cell A2 contains a UNIX timestamp 1341104400, then this formula

=A2/86400+25569

will return a number. And if you format that cell as a date, DD/MM/YYYY HH:MM:SS, then you'll read a pretty "01/07/2012 01:00:00" there.

Nice, isn't it? I am sure I'll be referring back to this post every once in a while
OOo 3.3.0 and Apache OOo 3.4.1/4.0.0, on Ms Windows 7 and Mac OS-X.
bns002.OOConfused
Posts: 1
Joined: Sat Aug 31, 2019 11:40 pm

Re: Convert UNIX timestamp

Post by bns002.OOConfused »

Ok... I tried the formula approach... slight variant that I found on "[Solved]" thread at viewtopic.php?t=1012

Code: Select all

=J3/86400+DATEVALUE("1/1/1970")
Should work just like

Code: Select all

=A2/86400+25569
I'm getting a negaive year, and no time.

Code: Select all

1565146800000	07/13/-13969 00:00:00
Any suggestions?
OpenOffice 4 on Windows 10
Bilbo47
Posts: 1
Joined: Thu Jan 12, 2023 8:49 pm

Re: Convert UNIX timestamp

Post by Bilbo47 »

This formula worked in LibreOffice 6:

Code: Select all

= DATE( 1970, 1, 1 ) + ( A1 / 86400 )
LibreOffice 6.4.6 on Win8.x
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