please help!

if this is the wrong thread please disregard. i hope someone help me about my problem for me its a big problem because im facing this 3 weeks ago until now,our cctv camera was not recording after 6th day at 8 pm in the evening, i dont know the permanent solution about this, what im doing is formatting the hdd and it will work and record again but still 6th day 8 pm will stop at the time, i dont want that cycle happen again, i want that begone, i want my cctv record like 15 days not 6 days without formatting, im not sure if my settings were wrong but please help me out about this, thanks!