Using UNIX timestamp has numerous uses, like cache busting of images or other requests, storing date as integer etc. Timestamp is a number of seconds since UNIX epoch, that is from 1st January 1970.
seconds based timestamp value, however it can be
Date.getTime() function, which
return milliseconds instead of seconds.
So first we get milliseconds since 1970, then divide by 1000
and round it. Hopefully some day
method will be added!