How to convert table string column(which is having time stamp in 1609999 format) to date format in looker

[RajiPrabha]

I have table which hold timestamp in number format but the data type of the table column is  string.

How to type cast it to timestamp or date format in looker ?

example:

In looker explore I could see value in 1600000 something like this , instead of 12/08/09 or 12/08/09 00:92:89 .

Any help will be appreciated  !