Help Creating Logic - Perform Work based on a Start Date only once in a while loop

I can't seem to get my head around this one. I feel like it's at the tip of my tongue but it won't come out.

I am basically trying to Write to an INI file accross the network on a daily basis. I want to put this logic in a While 1 .... Wend
loop that runs constantly and I am trying to avoid writing to this ini file multiple times in a day, I want to write to this ini file every day, but once a day. Hope this makes sense.
I only need help with a logic so that I only date this once a day. I do not need exact code nor syntax for writing to an ini file, it's all in the help document and thank god I can read.

Thank you for looking at this.

here is a sample

Local $var1 = "blah"


While 1
Sleep(Random(300000, 600000, 1));Gives me control over how often I am executing the code below....

...some code
...some code

WEnd