Apple retail employees were told this week that they may not request vacation days in late May, which could suggest Apple has something planned for the 10th anniversary of its retail stores.

Retail employees were told this week via e-mail that they may not request days off between May 20 and May 22, AppleInsider has learned. It was said that store managers are "very excited" about those dates, but no other details are available.

Gary Allen of ifoAppleStore.com said the most likely use for those days is a 10th anniversary event commemorating a decade of Apple's brick-and-mortar retail stores. He said it's likely that the company may do something anniversary-related to "attract a crowd" for a few days, but he hasn't heard any specifics.

New Apple products are expected to be announced in the coming weeks and months, particularly a refresh to Apple's iMac line of all-in-one desktops. However, new iMacs with Intel's latest-generation Sandy Bridge processors would not be an event that would compel Apple to institute blackout dates for its employees.

A May launch would also be too early for a new iPhone to debut. Though new iPhones have been released in years past in June, numerous reports have pegged Apple's anticipated iPhone 5 for a later September release.

Apple had employee blackout dates earlier this year as it prepared for two major product launches at the start of 2011: the Verizon iPhone 4 and the iPad 2.