Usually when a Date Range Sale has a problem it is due to one or more settings not being quite right. To check your sale details click Selling » Sales & Coupons then click on the name of your sale to edit the settings.
The first area to check is the dates in the Sale Details section. Make sure they are correct for the time frame you want to run your sale. The second thing to check is the section called
WHICH GALLERIES / GALLERY TYPES SHOULD THIS SALE RUN ON? You will need to choose at least one gallery from the Galleries section or one gallery type from the Gallery Types section. If you don't choose anything in this area the system won't know which gallery or gallery type you want to run your sale on.