How to convert date to string in unix shell -

i need convert date string

i have sql database running on unix box stores date in str eg:1371509465

i run query find if future dates exist in database

is there equivalent function php's strtotime in shell ?

linux:

date --date='@1371509465' 

mac os/x:

date -r 1371509465 

perl:

perl -e "print scalar localtime(1371509465);"