I bought it on 9-12-2019. It has automatic time adjustment via radio waves from 6 points around the world, depending on which time zone you are in. In Greece, it receives signals from England and Germany. You need to place it next to a window as far away as possible from electricity, mobile routers, and other devices in order for it to make the adjustment correctly. This is also mentioned in the user manual. You can manually adjust the time automatically as many times as you want during the day by pressing the bottom right button for a few seconds. However, before starting this process, you need to set the local time you are in and be in as empty an area as possible next to a window. I recommend the bathroom if it is as far away as possible from electricity and general radiation. In Greece, you select ATH, which stands for Athens. The automatic time adjustment is successful during nighttime hours and not during daylight hours. The automatic time adjustment occurs up to 6 times automatically, 5 times for China, from 00:00, 1 to 5 in the morning, every hour exactly. Yesterday, by chance, I looked at the time at 1 am and saw that it did start the automatic time adjustment, but it didn't succeed in the living room. However, when I went to the bathroom and started the automatic adjustment myself, it was successful. It has three signal levels for automatic adjustment, L1, L2, L3. Level 3 is the strongest signal, and then it adjusts the time, but it takes from one and a half minutes to several minutes to adjust the time automatically. Today, on 12/12/19, before 1 am, I hung the watch on the bathroom window, and as soon as it reached 1 am, the automatic time adjustment started, it found a signal on L3, and the process of automatic time adjustment took 4 minutes, and at 01:04 it automatically adjusted the time to 3 o'clock, it took 2 minutes to adjust. It has a world time feature, as you may have understood, the rest I won't explain because they are the most common settings. I shouldn't forget to mention that it has a solar panel and charges all the time, depending on the amount of light available. The manual emphasizes continuously charging the watch to keep the settings as accurate as possible and not to cover the watch with the clothes you wear. However, since it is not possible to do this continuously, I place it on top of the kitchen faucet under the spotlights of the cabinets, and as long as I am awake, it charges from there, and when I leave the house, I wear the watch. It also indicates how long it needs to charge after pressing the button for the watch's light, and also in the manual, it states how many hours of charging it needs depending on how many lumens each light emits, such as the living room lamp, bathroom lamp, sunlight, etc. It has a power save mode, which means that from 9 pm to 7 am, if the watch's screen doesn't receive light or the watch doesn't move, the screen completely turns off after 70 minutes, but all the functions remain active in the background. I won't write any more settings because the comment becomes too long, but in this link, you can see the watch's user manual that explains everything. Here is the link: https://support.casio.com/storage/en/manual/pdf/EN/009/qw3159.pdf The 3159 is the watch's module, which if I remember correctly, is the set of functions for this particular model. I have the same module since I bought it in Greece. I bought this watch because I like vintage digital watches, especially from the 80s and 90s. And you should know that this specific G-SHOCK is inspired by the first G-SHOCK that was manufactured in 1983, which is the DW-5000C, and as soon as I saw it, I was impressed by its appearance and simply bought it because I have loved this watch design since I was young. Something important that I forgot to mention is that the watch is programmed to automatically adjust the time from 1 to 5 in the morning every day, and once it finds a signal at 1, for example, and adjusts, it won't search again at 2, 3, 4, and 5. It will continue to function with the last successful adjustment. The next day, it will start the adjustment again at 1 until 5 until it finds a signal. However, it is better to see this in the manual because it is different from DST (Daylight Saving Time), it is a bit complicated, and that's why I emphasize reading the manual. Don't forget that if the watch is not next to a window, like in the bathroom, to find a signal, it will work with the most recent successful adjustment. If you didn't understand anything from the manual, start a discussion here on Skroutz in the product section, and we will talk there so that others who don't understand English well can see. Not that I am excellent, but I understand quite a bit. You should know that this watch, because it is not cheap, has a different operation and more settings than the cheap Casio watches, and it is necessary to read the manual; otherwise, you will struggle with some settings. I wrote a lot, but not everything because this watch is much more complicated than the F91 or F105, for example, which are very easy to adjust. You will understand it once you read the manual, which, you should know, is not difficult but not as simple as the cheap CASIO watches that cost 15, 20, or 30 euros. Update 13-12-19, 2:58 and about 30 seconds in the morning when I tried to manually update the time, this time with the bathroom window open, the watch adjusted even faster. It was adjusted in about one and a half minutes, meaning it went straight to 03:00 and made the characteristic sound "tit tit" and adjusted. I simply opened the bathroom window and it caught the L3 signal level in a few seconds and adjusted. This is a very good feature. Next time, I will try it outside the house and will update.