I want to make a little code that displays a different string everyday.
for example I have 100 strings. I want that when a user opens my site they'll see one of the strings that day. the next day they'll see another string..and so forth.
so far I thought about putting all the strings in array and give every string a hardcoded date on which it will displayed, and then with a simple if statement the correct string is going to be displayed.
is there any known(better) way to do this?

why you not creating database for string u can add it and next day delete all string with one line query and add new string.

I don't want to create a DB for this.. it's really something tiny that I want to be done with as little code as possible.
and what I wonder about is not how to save the strings but how to display a different one everyday without hardcoding the dates.
i want to set the strings once (not change the string everyday) if I set 30 strings, after 30 days I want the loop to repeat itself (so deleting a string each day won't work cause I'll have to insert it again when I'm out of strings).

You'll need to store somewhere (in a file perhaps) which array index is the current one, and increase that daily.

how do i update the index only ONCE a day?

With a scheduled task (cron job).

ok, any other suggestions on doing this inside the code itself?.. i see hardcodding the dates is the only option if I want the code to do it and not something like cron job?

If you store the current date with the index, you can check if it has changed and overwrite it.