It is of the utmost importance that you do not change the system time backwards in time on the computer that is running the Microsoft SQL Server Notification Services manually. If you do, Microsoft SQL Server Notification Services can crash, and this will result in data loss (loss of notifications.)
Therefore, you should set this computer up to automatically adjust for daylight savings time. Follow this procedure:
Open Control Panel, Date and Time.
Click the Time Zone tab.
Check that "Automatically adjust clock for daylight savings changes" is selected.
Setting the time forwards does not provoke a crash in the same way, but will cause notification messages not to be sent.