I don't think tou can set date and time manually. The best way set time and date is to take the watch outside to a area that's free of trees and buildings press enter and select an activity such as running or cycling.and let the watchconnect to the satilites. This will set the timezone and sync time to gps.
You don't need to start an activity or sync with a computer.
Just press and hold the Start/Stop button to initiate saving your current location -- you'll see a message saying "Waiting for GPS". Once the watch gets a satellite fix it will set the date and time from the GPS signal. You don't need to actually save the location, just press the Back button after your location information is displayed and the date and time have been set.
To set the time manually go to Settings, System, Time, Set Time then choose Manual
However, as noted there are ways to set about getting the date and time by connecting to phone, gps, or computer. I’m curious as to why your date is 5 days off.
