[Eikinskjaldi]

both the post and thread tables contain a dateline field which contains the time of creation in 'seconds since the epoch". You can convert to and from a dateline and an actual date using the from_unixtime and unix_timestamp functions. However, what you really want to know is what is the unix time for 1 month ago.

If we assume naively that a month has 30 days, then the number of seconds in a month is 60x 60 x 24 x30 = 2592000

We can find out the time now by using the now function

So, one version which will do what you want to do is

"select * from post where unix_timestamp(now()) - dateline <= 2592000