Create of views with specific date filter

Hi

I ned to create three different views, but the baseline is the same:

I need to do a filter on a date field (installation date) where Installation date is 14 days ago, 3 months ago and 6 months ago (each have their own view)

I know that I can set the filter to Older than X days or X months, but then I will get every record with an installation date before f.x 14 days, and I only want those with installation date = today's date - 14 days (3 months or 6 months)

Does anyone know how to get around that? 

Thanks!