Guys I'm very new to Cisco so please have patience.
I have a Cisco 2620 V 12.3(26)
I would like to know how to set the correct time and date?
Thanks in advance.
The fact that your router does not maintain time over a reboot/reload does not have anything to do with the config and whether it was saved or not. It has to do with the router hardware. Some routers have a clock chip that maintains time over a reboot/reload. But the 2620 does not have this. So it goes back to default time when it boots.
The solution suggested by Kev is the correct way to set time once the router is running. But that time is not preserved over a boot process and you would need to set the time each time the router boots.
If the router has access to the Internet then an option would be to configure the router to use NTP and to learn correct time from an Internet NTP source (there are many available). If you run NTP then after the router boots it will learn the correct time and you will not need to worry about it.