Because it wouldn't be a timed response.
Generally you find most people who want timed are trying to ensure it doesn't look like an autoresponder.
This is pretty useful especially if posting to CL, as not only does your message not look so canned but you get some breathing space before your advert is flagged.
The "easist" / cheapest way to do this is simply set up outlook, then have two gmail accounts
On day 1 you send to gmail 1 on day 2 to gmail 2 , forward them in gmail to seperate pop3 accounts in outlook.
Then just set up a rule and hit send receive 24 hours after you sent the responses to gmail 1.
It's a free delayed AR basically.
Not ideal but works perfectly,