Specials Available and Expiry Dates

Our special ended a day early.
The first date of the special was entered into Available Date.
The last date of the special was entered into the Expiry Date.
It seems that the special expired at the beginning of the expiration date and not the end of the expiration date.

What are the rules for entering dates for specials? And are the rules the same for coupons, salemaker and banners?

Thanks for any help!

Jan

Specials start on 08/01/2009 ... this means that at midnight, 08/01/2009 the special will begin ...

Special expires at 08/31/2009 ... this means that at midnight, 08/31/2009 the special will end ...

If you want the Special to run through the day of 08/31/2009, then use the expiration date of: 09/01/2009 so that it ends at the stroke of midnight on 09/01/2009 which is 1 second after the end of the 08/31/2009 23:59:59 ...