Shell script to get difference between two dates

Question

If there are dates as 2010-06-01 and another as 2010-05-15

Using shell script or date command how to get the number of days between the two dates

Thanks..

Answer 1

Using only date and shell arithmetics:

echo $((($(date -d "2010-06-01" "+%s") - $(date -d "2010-05-15" "+%s")) / 86400))