Converting unix time into date-time via excel

Question

Trying to convert 1504865618099.00 Unix time into a readable date time. I tried this:

=(UNIX + (\"1/1/1970\"-\"1/1/1900\"+1)*86400) / 86400

Answer 1

in case the above does not work for you. for me this did not for some reasons;

the UNIX numbers i am working on are from the Mozilla place.sqlite dates.

to make it work : i splitted the UNIX cells into two cells : one of the first 10 numbers (the date) and the other 4 numbers left (the seconds i believe)

Then i used this formula, =(A1/86400)+25569 where A1 contains the cell with the first 10 number; and it worked