I had the same problem with an old Pentium like that. AcaCandy is right on about living with it if the time is not an issue, just a convenience. In my case I had a few programs on my old one that needed updated, and wouldn`t update unless the date was correct, so what I did was download a program called Atomic Clock, there are also others , do a google check to find one. I am trying to recall it has been a while, and depends on whether you leave your comp on all the time as some do, or turn it off. If you leave it on all the time, the atomic clock should keep the time all the time. If you turn your comp off, it will loose the time, so when you boot up, the time will be off, but when you go online, the clock will ping(check) the time and adjust it to the correct time and date. Don`t know if this will help you out in your situation, but it is something you can try if you wish.
Regards
Peters321