[Trac] date functions in report queries

[Sam Keen]

I was wanting to make some custom queries such as 'modified in last five days'

so far I have...

SELECT
id AS ticket, changetime AS modified, component, status, severity,
priority, owner, time as created, summary
FROM ticket
ORDER BY modified DESC

but I would like something to the effect of...

SELECT
id AS ticket, changetime AS modified, component, status, severity,
priority, owner, time as created, summary
FROM ticket
WHERE modified > [five days ago]
ORDER BY modified DESC

Are there date functions that can be used directly in the SQL or some
other technique to accomplish this.

Thanks in advance,

Cheers,
Sam