Using date command is pretty handy way to covert unix timestamp to string format and vice versa. This can also be used to print unix timestamp. Here are some handy date commands (using gnu date).
Print unix timestamp
Print unix timestamp in seconds (Mac or Linux) $ date +%s 1438190744
Print date in YYYYMMDD format
$ date +"%Y%m%d%H%M%S" 20150729230603
Print yesterday’s date
date --date="yesterday" +%s
You can also use “-1 day”, “+2 day” etc.
Convert unit timestamp to string format
$ date -d @1438364922 Fri Jul 31 23:18:42 IST 2015
You can print custom format also. e.g.
$ date -d @1438364922 +"%Y%m%d%H%M%S" 20150731231842
Additional steps for Mac
In case you are using Macbook, it comes with non GNU date. To install gnu date, install coreutils.
$ brew install coreutils
This will install gdate in addition to others utils on Mac as part of coreutils. Either replace date with gdate or edit the PATH envrironment variable. To edit the PTAH put these in your ~/.bash_profile:
PATH="/usr/local/opt/coreutils/libexec/gnubin:$PATH" MANPATH="/usr/local/opt/coreutils/libexec/gnuman:$MANPATH"
