Message Delay

I'm use photon realtime dotnet with unity for host game room & photon realtime js for html client

I have notice.
I keep datetime that I send and receive message (response_c - response_s ) it use 0.8 sec
why message travel is use time more than ping too mush.

Send Message : response_c : 2016-07-04T22:32:46.2513329+07:00
Receive Message content : Change State to select. : 2016-07-04T22:32:46.2513329+07:00
Receive Message content : response_s : 2016-07-04T22:32:47.0018134+07:00
ping 51