How to set time in g shock wr 20 bar
"G-Shock WR20BAR" could mean hundreds of different G-Shock models. If yours is an all digital G-Shock, the answer is fairly simple. When looking at the watch face, the upper left corner button is the "ADJUST" button. Press and hold the ADJUST button for a couple of seconds. You should start to see something flash on the display. Some models will have many options to select in ADJUST mode. To scroll through them, press the MODE button, which is in the lower left corner. You set the hour, minute, seconds, month, date, and year each separately. When you are done, press the ADJUST button again and you'll be back to normal time keeping.
If you want to learn more about your G-Shock, there is something called a "MODULE" inside it that is the brains of the watch. You can find that on the back of the watch, outlined in a rectangle. Usually a 4 digit number. You can download the manual for your watch using that number, if you enter it on a CASIO website: