U.S. daylight saving time zones change in 2007. However, these changes do not occur on the correct day on Microsoft Windows CE 5.0-based devices. Windows CE 5.0 changes the time on the first or last Sunday of the month. Windows CE 5.0 does not change the time on the second or third Sunday of the month.
There is an update available for CE 5.0 that addresses this issue - take a look at the following KB921095 Knowledge Base Article (KB Article).