Welcome to Just Answer.com,
Could you please tell me the module number which is printed on the back of your watch. It may be a 3 or 4 digit number.
Please click on the link below to download the user manual for your watch
Kindly follow the instructions mentioned in the "Current time Setting" in page number 1 to set the Home time zone and subsequently follow the steps "To set date and time manually" which is explained in page number 4.
The instructions are explained step-by-step. I hope this will help you solve the issue.