Your can use gTimeSync to synchronize the clock on your mobile device with atomic time servers on the Internet.

use "gTimeSync.exe -u" for unattended sync (for example in scheduler job)

The product is released to the following editions: for the .Net Compact Framework 2.0 and above. The product is shipped with the full source code (by request). Program OS Support: Windows Mobile, Windows CE. Program System Requirements: .NET Compact Framework 2.0.