Slightly strange question, but hopefully someone can help.
In essence, if the time was 12pm the the elapsed percentage would be 50%, 6am would be 25% and 16pm would
I dont know php but is there any way to get the current date witch i guess :P can you extract the hours out of this or minutes how exact do you want it to be?, Current hours/24 * 100 :P current minutes/1440 * 100