Is there anyway to disable sleep time

In my watch (Garmin Instinct), I can turn off the Sleep Time (while keeping the Do Not Disturb option for manual control) in the settings: Menu (long press of the middle left button) >> Settings >> System >> Do Not Disturb >> Sleep Time. Another possibility might be setting the sleep time very short or perhaps even null.

Do u know how to turn off sleep mode altogether 

I did not really look at it closely, but the first thing that what I'd try, is setting the bed time and the waking up time just a minute apart. In that way the sleep mode will stay active just a minute. Not sure what happens if the times are identical, and whether than the sleep mode takes all the 24 hours, or oppositely 0 hours, but you can try it certainly too.

That told, by this you disable the sleep monitoring too. If you just want to get rid of the specific watch face during the Sleep Mode, there is a setting for it. To get there, open the Sleep widget, and long press the menu button. 

Thanks for that.  When in sleep mode it stopped sending security alerts re camera's to my watch while I was sleeping.  Don't really need the sleep mode telling me how I sleep.  thanks again

For enabling notifications, you do not need to disable the Sleep Mode. Simply disable the the DND mode during sleep, and also disable Battery Saver during sleep. Without the sleeping metrics, many of other features will be impacted - for example the HRV Status, and all the other performance metrics depending on it.