Dear Survivor,
This is the first time I see it. On your side: You have no problem on other MTA servers ? This is only a problem on MTA DayZ ? If your server is hosted on a dedicated server, can you send me the IP of it ?
This seems to come from night shader.. You can update your version of MTA:DayZ to 0.9.7.4a. The latest version will disable the night easily on the "cfgClient.lua" file.
I haven't any problem on other server's. I installed it on local server.
UPDATE: Disable "enablenight" variable and that's work fine now. Thx for help!