How do you display dates by date

Hello.
I’ve had a scout around the documentation, but cannot really find what I need. I have read about ‘offset’, but you can’t seem to pick a date with that.

my problem is this… I have an events guide, and post the events six weeks in advance. but i only want the main page to display the events that are less than 3 weeks away. (so i want to hide everything that was posted between 3 and 6 weeks ago.)

does anyone know a way of sticking something in the loop to do that? many thanks!