Delay of mail transmission of periodic reports.

Delay of mail transmission of periodic reports.

There is a phenomenon to be delayed one hour from November 4, 2013.

It did not occur until November 13, 2013.
It is delayed by one hour after 14th November 2013.
Although not changing the setting of the outgoing time.
There is no difference in the record update time of ZohoCRM and local time.

Please give me the investigation.