Allowing spiders between certain times

[Dilmah]

Call this thinking out loud if you will...

I was wondering if it's possible to allow search engine spiders to visit my site only between certain hours.

My site has a clearly defined low-traffic time between about 11pm and 8am, and I wanted to allow spiders in only then, so they don't overload the server during times were general traffic is higher.

I don't want someone to post a big chunk of code for me, or anything like that - i want to do it for myself - no point having someone else do my dirty work. lol

The way I was thinking was to put a conditional somewhere, were PHP can determine the server time, and if it's outside those hours it adds a no-index meta tag. Would this work? Or am I missing something.

Cheers