If just a numeric value representing the time is okay for your purposes, see perlfunc:time - it gives you a large integer value representing the current time to the nearest second.

If you want the filenames to be easily readable as date and time by humans looking in directories then look at perfunc:localtime.

BTW. If your had typed "time" into the white box at the top of your screen and clicked the search button, it would have taken you directly to the first reference above.

As for creating the file, type "open" in that same box and you will get a whole host of information, examples and further links for you to explore.

If you get problems, post your code and explain what your problem is, and someone will help your further.