Find all the dates in the calendar week?

I have a table of events with a column which stores datetimes. I want to check
if a datetime is inside the current calendar week (i.e. from the previous
monday to the next sunday). The purpose is to SELECT all the events of the
week.

I cannot find a way to do it in SQL? Did I miss something?

[If there is no SQL way, I'll hack it in a Perl script. Code or suggestions
welcome.]