Their website claims they are one of the original digital stopwatches, and reportedly was the official stopwatch for the 1996 Atlanta Olympic Games. Some reviewers complained it was hard to figure out how to set the date, time and calendar, which was true for me, even WITH the instructions, which are NOT included. The description of this stopwatch on the ACCUSPLIT website states the instructions ARE included, BUT the listing here on Amazon has a disclaimer emphasizing the instructions are NOT included. Fortunately, the Amazon listing has link for a PDF file of the instructions, which is dated 2020. I discovered the ACCUSPLIT website also has a copy of instructions for this stopwatch, dated 2015, that were slightly different from the instructions available in this listing. It was not possible to include the PDF files of the two variant instructions in this review, so I uploaded screenshots of the two variant instruction; I hope the print is still legible. With some help from the confusing instructions, and lots of Trial and Error, I was finally able to get the correct TIME, and numbers corresponding to the Month and Day programed into this device, so when not being used as a stopwatch, it will display TIME like a watch. And for some reason, you are also able to store an unchanging TIME in memory. You can set it to display the watch time as AM / PM or 24 hr time. The instructions tell you to go to the ACCUSPLIT website for an explanation on how to change the battery, implying if you aren’t careful, it might compromise the claimed ‘waterproof’ feature. Searching their website provided NO DESCRIPTION on how to change the battery. The ’new’ stopwatch I received, was DEAD ON ARRIVAL! (Accusplit claims this stopwatch is supposed to have a 5 year battery!)As a last resort, before having to go through the hassle and wasted time of returning it back to Amazon, and waiting for a replacement, I got a replacement battery. Upon examining the back of the stopwatch, observed 6 very tiny screws. One reviewer complained that she had stripped out the screws trying to change the batteries, so I took the stopwatch to a hardware store, to insure I bought the correct special small ‘jewelers’ type screwdriver. The screws were quite tight (probably for the ‘watertight’ claim) but with care, overcoming the initial tightness, fortunately was able to get all 6 screws unfastened. NOTE: perform this procedure in a carefully controlled environment, like on a white towel, (my screws were black) to ensure the tiny screws don’t roll away or get lost! Fortunately, after putting in a new battery, the stopwatch started working again! BUT, after carefully replacing the screws (not forcing them, because sometimes the screws felt like they were initially cross threaded!) After replacing the screws, I intentionally did NOT ‘over tighten’ them, to avoid stripping them out. The claimed ‘watertightness’ is now probably compromised, but I don’t plan on dropping it in water! A sticker on the back of this watch, in very tiny print, stated the warranty was good until October 2021. After that, if you pay $12, they will fix it until October 2025. Since the Battery was Dead On Arrival, I wonder if this stopwatch spent several years sitting on a shelf in some warehouse? In spite of it all, I still like this stopwatch, since I’m not going to use it for athletic events. I’m going to use it while watching specific television shows on different streaming television channels, to time the length of commercials they pad into the TV shows, to determine if any particular streaming channel, is adding in more commercials, compared to a different streaming TV channel!