There is a serious problem with one of my servers time.
At some random hours (5:59 localtime in the following example) it goes 1 hour back and keeps doing this again and again next times it reaches 5:59. Like this: 5:59->4:59 … 5:59-> 4:59 and so on. It stays in the loop until I manually update its time.
The server OS is Windows 2008 R2 Standard x64, acting as a standalone web server on the internet. time zone (UTC-05:00).

system log:

Information 4/13/2012 5:59:34 PM Kernel-General 1 None
Information 4/13/2012 5:59:34 PM Kernel-General 1 None
Information 4/13/2012 5:59:34 PM Kernel-General 1 None
Information 4/13/2012 5:59:34 PM Kernel-General 1 None
Information 4/13/2012 5:59:34 PM Kernel-General 1 None
Information 4/13/2012 5:59:34 PM Kernel-General 1 None

all of the above entries have same content:

The system time has changed to ?2012?-?04?-?13T21:59:34.500000000Z from ?2012?-?04?-?13T22:59:34.500000000Z.

Details XML View:

- <Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
- <System>
  <Provider Name="Microsoft-Windows-Kernel-General" Guid="{A68CA8B7-004F-D7B6-A698-07E2DE0F1F5D}" /> 
  <EventID>1</EventID> 
  <Version>0</Version> 
  <Level>4</Level> 
  <Task>0</Task> 
  <Opcode>0</Opcode> 
  <Keywords>0x8000000000000010</Keywords> 
  <TimeCreated SystemTime="2012-04-13T21:59:34.500000000Z" /> 
  <EventRecordID>4060</EventRecordID> 
  <Correlation /> 
  <Execution ProcessID="4" ThreadID="80" /> 
  <Channel>System</Channel> 
  <Computer>********</Computer> 
 <Security UserID="S-1-5-18" /> 
  </System>
- <EventData>
  <Data Name="NewTime">2012-04-13T21:59:34.500000000Z</Data> 
  <Data Name="OldTime">2012-04-13T22:59:34.500000000Z</Data> 
  </EventData>
  </Event>

Any idea about what’s going on?
Thanks