Bashscripts.org

So i have a littel problem..i know its basic..but im a newbee..

i want to make a script, wich sais which day is that date what i write for it..

so example i write 20120510 (yyyymmdd)
and it write thursday..
and if date is not valid it have to write that "its not a correct date."

i tried the date
its write the correct day..but how decide the program that the date is not valid if a write ex 20011535?

thx in advance

The 'date' command can deal with all kinds of input, and will tell you if the date you've given it is invalid. You should get output like: invalid date `20011535'

Is your question about validating the input BEFORE it's passed to the 'date' command, or do you just want to intercept the output of 'date' and print your own message if the date is wrong?

yes i want to check the validity of the date before 'date' command

It sounds like you want to make valid only one date(1)'s --date input string. What's the point of doing this,
since the said command's output will always be identical for different input strings meaning the same thing?

Consider this as a feature and use date(1) to check whether the given date was valid, like so: