How can we get weekday based on given date in unix

Question

From a given date in %m-%d-%Y format we should determine what day it is.

Example: for the date 09-01-2017 output should be Friday

Answer 1

Very simple. Just use the date command itself with correct options.

$ date -j -f '%m-%d-%Y' "09-01-2017" +'%A'
Friday

Answer 2

If you have your date like this:

d="09-01-2017"

you need to reformat it to "YYYY-MM-DD"

date -d $(echo $d|awk -F- '{print $3 "-" $1 "-" $2}') +%A # DOW