Check N serie R6679202

They don't have battery's ,it is a analogue watch, winding .

http://www.c2coffer.com/search/rolex-oyster-perpetual-datejust-16-78678.html
Try this link to get more details. Gopakumar Gopalan Google

this link will help you
Identify Counterfeit Fake Rolex Watches Rolex or Replica Don get Screwed

https://youtu.be/utu7EA8Uq88
Watch the above

Reset the time, day and date manually from scratch. Check for another 24 hours. If the problem persists that means there is interference between day and date wheels and in this case you will need watchmakers help, as to correct such a fault the watch needs to be disassembled almost completely.

You can get user instructions for their web site http://www.rolex.com/en#/rolex-watches .

Click on "collection" and then choose your watch from the list (incidentally, I couldn't find "daytona oyster" but "Daytona" and "Oyster"!).

At the bottom of the page you will find "downloads".

Click on this and then on "user guides".

The stem has 2 settings...the first pull[click] will be for time only. then pul lit harder and it will come out a little farther and you set the day and date.. Christmas or B-Day ...Congratz..

Unfotunately for you- your Daytona is fake.

Usually to change the date you need to have the crown pulled out to a position that is between the "closed" position and the position where it will move the minute/second hands.

Depending on how old the watch is, It may be quick set or older models are not quick set. In older models you need to unscrew the crown, pull out the crown and rotate the crown to set the time, and in order to set the date rotate the hour hand past 12 twice in order for the date to change. Set the date first and then set the hour and min. For quick set models unscrew the crown and pull it out to the fist click this position you can "quickly" set the date by rotating the crown. Set the date and then pull out the crown to the second position out. Rotate the crown to set the hour and min. Then push the crown back in and screw it down.