How do I convert a date from Unix time to string, in a script?

To convert a date from string to Unix time, I can use date --date "2012-02-13" +%s.

How do I do the opposite, from Unix time to string?

How do I convert a date timestamp to date?

We can convert date to timestamp using the Timestamp class which is present in the SQL package. The constructor of the time-stamp class requires a long value. So data needs to be converted into a long value by using the getTime() method of the date class(which is present in the util package).

You can use date --date @datetime:

[foo@bar ~]$date --date "2012-02-13" +%s 1329055200 [foo@bar ~]$date --date @1329055200 Mon Feb 13 00:00:00 EST 2012 [foo@bar ~]$date --date @1329055200 +"%Y-%m-%d" 2012-02-13

I'm not sure where the '@xxxx' is documented though!