Perhaps the examples here would help you:
http://dev.mysql.com/doc/refman/5.0/en/date-calculations.html
> -----Original Message-----
> From: Noel Butler [mailto:noel.butler@stripped]
> Sent: Saturday, December 26, 2009 6:47 PM
> To: mysql@stripped
> Subject: anniversary selects
>
> Hi,
> Hope we all had a great Christmas!
>
> I am trying to run a query that selects a member every 365 days so we
> can send them a domain reminder.
> For my test (because i'm too lazy to count out someone with
> hundreds of
> days :) ) I am using a known member at around 27/28 days
>
> Now if I use this if finds the member, it doesn't find them if I go
> under to say 27 days, I've used the DATE_SUB many times before, but
> never for an exact match.
>
> SELECT * FROM `member` WHERE AddedOn>=DATE_SUB(CURDATE(), INTERVAL 28
> DAY)
>
> Now trying to get an exact match, fails.
> SELECT * FROM `member` WHERE AddedOn=DATE_SUB(CURDATE(), INTERVAL 28
> DAY)
>
> Also tried one by one up to 30 and down to 25 days,
>
> Would someone please mind slapping me a good one reminding me
> what I've
> done wrong :)
> I thought CURDATE ignored the hours/mins/secs etc, but it
> seems it does
> not?
>
> Thanks
> Noel
>
>