quick and easy way of validating a date format of yyyy-mm-dd and returning a boolean

if date -d 2006-10-10 >> /dev/null 2>&1; then echo 1; else echo 0; fi

On CentOS at least, date returns a boolean for the common date string formats, including YYYY-MM-DD. In the sample output, you can see various invalid dates returning 0 whereas a simple regex check would return 1 for the invalid dates. -d, --date=STRING display time described by STRING, not `now' The version of date on OS X does not appear to have this same option.

Sample Output

# if date -d 2006-10-10 >> /dev/null 2>&1; then echo 1; else echo 0; fi
1

# if date -d 2006-40-10 >> /dev/null 2>&1; then echo 1; else echo 0; fi
0

# if date -d 2006-13-10 >> /dev/null 2>&1; then echo 1; else echo 0; fi
0

# if date -d 2006-11-31 >> /dev/null 2>&1; then echo 1; else echo 0; fi
0

By: SteveGoossens

2013-01-10 10:35:15

date echo date validation

1 Alternatives + Submit Alt

quick and easy way of validating a date format of yyyy-mm-dd and returning a boolean

Quick and easy way of validating a date format of yyyy-mm-dd and returning a boolean, the regex can easily be upgraded to handle "in betweens" for mm dd or to validate other types of strings, ex. ip address. Boolean output could easily be piped into a condition for a more complete one-liner.
This is sample output - yours may be different.
-1

echo 2006-10-10 | grep -c '^[0-9][0-9][0-9][0-9]-[0-9][0-9]-[0-9][0-9]$'

rez0r · 2009-05-11 22:18:43 7

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What do you think?

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