Parse Date in Bash

Question

How would you parse a date in bash, with separate fields (years, months, days, hours, minutes, seconds) into different variables?

The date format is: YYYY-MM-D

Answer 1

$ t='2009-12-03 12:38:15'
$ a=(`echo $t | sed -e 's/[:-]/ /g'`)
$ echo ${a[*]}
2009 12 03 12 38 15
$ echo ${a[3]}
12