Forum Moderators: coopster
1) How many hits you have on your page
2) Do you display graphically the date and time
if you have a low hit rate and don't display the date and time, then it's a low overhead. But given a hit rate of 10000 a day or so could cause lag. Also, displaying them causes the page to also have to process the date and time, which adds additional lag.
As a short answer, no, it should not unless extensive processing with it.
I wouldn't worry about it at all. I bet if you profile it you will find that your CPU wouldn't even break a sweat doing that date calculation 10000 per second.
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