stamp date on md5sum

[Theadmin77]

I know this is a stupid question but ....im stuck ...
I have 2 files were i have to perform a md5sum check , the results (hash string) output to a file were must be stamped with the date and time the validation was performed .

I got the first part :
md5sum file a file b > results.txt
But how do you stamp those files with the time and date ??

Any help will be appreciated

[pbmods]

I got the first part :
md5sum file a file b > results.txt
But how do you stamp those files with the time and date ??

Something like this, perhaps?

md5sum filea fileb > results_`date "+%Y-%m-%d"`.txt