Converting time stamps in excel to dates

I have a very large excel spread sheet that has a column of time stamps. Does anyone know convert that over to a date? Is there a function I can use? I tried format cell date but that doesn't work. My file is 91,568 KB. If there is a simpler way to this that would be great. I'm open to ideas.

Thank you in advance :)

P.S. I don't know any programming languages

Use this formula and set formatting to the desired time format:

=(((COLUMN_ID_HERE/60)/60)/24)+DATE(1970,1,1)

Source: http://www.bajb.net/2010/05/excel-timestamp-to-date/ Tested in libreoffice

A timestamp is the elapsed time since Epoch time (01/01/1970), so basically we have to convert this time in days, and add the epoch time, to get a valid format for any Excel like spreadsheet software.

• From a timestamp in milliseconds (ex: 1488380243994)

  use this formula:

    =A1/1000/86400+25569
  

  with this formater:

    yyyy-mm-dd hh:mm:ss.000
  

• From a timestamp in seconds (ex: 1488380243)

  use this formula:

    =A1/86400+25569
  

  with this formater:

    yyyy-mm-dd hh:mm:ss
  

Where A1 is your column identifier. Given custom formaters allow to not loose precision in displayed data, but you can of course use any other date/time one that corresponds to your needs.

If you get a Error 509 in Libre office you may replace , by ; in the DATE() function

=(((COLUMN_ID_HERE/60)/60)/24)+DATE(1970;1;1)

below formula worked form me in MS EXEL

=TEXT(CELL_VALUE/24/60/60/1000 + 25569,"YYYY-MM-DD HH:MM")

CELL_VALUE is timestamp in milliseconds

here is explanation for text function.

If your file is really big try to use following formula: =A1 / 86400 + 25569

A1 should be replaced to what your need. Should work faster than =(((COLUMN_ID_HERE/60)/60)/24)+DATE(1970,1,1) cause of less number of calculations needed.

=(((A1/60)/60)/24)+DATE(1970,1,1)+(-5/24)

assuming A1 is the cell where your time stamp is located and dont forget to adjust to account for the time zone you are in (5 assuming you are on EST)

This DATE-thing won't work in all Excel-versions.

=CELL_ID/(60 * 60 * 24) + "1/1/1970"

is a save bet instead.
The quotes are necessary to prevent Excel from calculating the term.

Be aware of number of digits in epoch time. Usually they are ten (1534936923) ,then use:

=(A1 / 86400) + 25569    

For thirteen digits (1534936923000) of epoch time adjust the formula:

=(LEFT(A1,LEN(A1)-3) / 86400) + 25569    

to avoid

###################################

Dates or times that are negative or too large display as ######

See more on https://www.epochconverter.com/

The answer of @NeplatnyUdaj is right but consider that Excel want the function name in the set language, in my case German. Then you need to use "DATUM" instead of "DATE":

=(((COLUMN_ID_HERE/60)/60)/24)+DATUM(1970,1,1)

AD ticks to datetime format: =A1/864000000000 - 109205

i got result from this in LibreOffice Calc :

=DATE(1970,1,1)+Column_id_here/60/60/24

This worked for me:

=(col_name]/60/60/24)+(col_name-1)

Use this simple formula. It works.

Suppose time stamp in A2:

=DATE(YEAR(A2),MONTH(A2),DAY(A2))