Getting the EPOCH time for a custom date values in bash

Question

I need to write a bash function to return the EPOCH time for a custom date, in the future.

I use date and time in the formats;

date=20130122 # i.e. 2013 01 22
time=1455     # i.e. 14:55

Can I get the EPOCH time with these values?

Does anyone know a solution?

Answer 1

date -d "$date $time" +%s

Would work in GNU date.

For BSD date (included with Mac OS X), the command would be

date -j -f "%Y%m%d %H%M" "$date $time" +%s

(-f is needed to parse your date and time as given; the default format would require "012214552013" to specify the same time)

Answer 2

Short answer:

date --date "20130122 1455" +%s

This will give you the date in epoch.

Or if you use variables, just replace the date and time like this:

d=20130122
t=1455
date --date "$d $t" +%s

And try to avoid using "date" and "time" as variable names, since they easily could be misunderstood as commands (they are both valid commands). This to increase readability.