Windows 10 - Time and Date Changes to Time Only

drcard! Thank you so much! Here's the result.

MARGE ANSWERS:
1. Right click the date and time in the Task bar and select Adjust date/time from the menu that pops up. This is the settings for the Date & Time. GOOD

2. With Date & Time selected in the left pane, look in the right pane at Set time automatically. Is it set to On?
YES

3. If it is, set it to Off. OKAY, DID THAT.

4. Now look under Synchronize your clock. What was the date and time of the Last successful time synchronization?
Mon 11/30/20 7:13:38 p.m.

5. Does that time coincide when the date disappears or reappears?
NO. IT ALWAYS HAPPENS AT MIDNIGHT.

6. Now press the Sync now button. What happens?
It says last successful time synch was exactly when I hit the “sync now” button.


7. Now close the setting window. Count to 20 and reopen the settings window as you did before.
OKAY, DID THAT

8. Turn the Set time automatically back On. What happens
(didn’t have to turn it back on. “set time automatically” reverted back to “on”)

9. and does the last sync time change?
NO

The answers to these tests will help locate where the problem is.
My gut says it is the CMOS battery on your motherboard going out. The CMOS battery on your motherboard is a large watch battery about the size and thickness of a US quarter. But, that is why we are testing to be sure.
For those that follow this thread, I will explain what the tests reveal when I respond to the results of the testing.

Hi Marge,

Analysis of your answers and what they tell:

When a PC boots up it gets the current time from the BIOS. The BIOS gets the time from a on-board clock that runs on power from the plug in the wall or if no external power runs on a watch battery to keep the clock running. Like all watch batteries they cycle between working and not working when they are dying. For a PC this could give the incorrect time. After the PC boots up and while the PC stays on the time is kept by Windows, but Window's clock is very inaccurate and must be adjusted to the correct time. Windows has a service to do this by checking certain web sites that keep accurate time and resetting the PC clock to the correct time. If anything prevents this service from connecting to the web site this will prevent Windows from adjusting the time to the correct time and thus the wrong time.

The turn the Set time automatically Off is basically turning off the time check service. Turning it off and then turning it on will reset the service which may have been hung. The fact that it turned itself back on does cause concern, but we will address that latter.

Since the Date & Time since last synch does not match the times when the Date & Time displayed changes, trouble with the synch or server is not the problem.

After waiting 20 minutes (to make sure all server connections have been stopped) you should have been able to turn the set automatic date & time back on, but was already on. I am concerned that the service couldn't be stopped and restarted, but I don't think it is part of the problem since the it is working and the synch times do not match the problem times.

I believe the problem is in the date format you use since the problem is affected only when the date is changed (at midnight of each day). The date format that you use is a newer date format from updates to Windows or add-ins.
Some systems have trouble with the 3 letter day of the week versus the day of the week spelled out.

We are going to reset those format settings to full day of week spelling and see if that corrects your problem.

Side Note to other readers: The following instructions are how to change how the Date and Time appear in the Task Bar.

Change Date & Time Format to show day of week:

Note: Take your time and follow the instructions exactly as these settings are deep in Windows and take many steps to get to them without direct coding.

> Right click the Date & Time in the Task bar and select Adjust date/time from the menu.
> In the Date & Time Settings that opens select Region in the left pane.
> Scroll down the right pane to belowRelated Settings and select Additional Date, time & regional settings.
> This opens the Clock & Region control applet.
> Under Region select Change date, time or number formats which opens the Region format window.
> In the Region formats box at the bottom of the Formats tab press the Additional settings button which opens the Customize Format box.
> In the Customize Formats box select the Date tab.
> About middle of the Date page is a section labeled Date formats and under that is Short date: with a box to the right of it. The format in that box determines the format displayed in the Task Bar.
> The current setting should be highlighted awaiting editing. Your current sett will be ddd M/d/yyyy which yields (Eaxmple):

9:09 AM
Tue 12/1/2020

Note the space between the day of the week the month

> The setting for the full day of the week name is dddd, M/d/yyyy which yields (Example):

9:09 AM
Tuesday, 12/1/2020

Notice the comma and space after the day of the week and notice the coding for 3 letter day or week is ddd and full name is dddd,. Also note the comma with dddd and no comma with ddd. If you include the comma with ddd no date will show... only time. If you don't have the comma with dddd then no date will show and only time. The system will only allow certain formats and any slight change with the selected format results in that formatted item not displaying.
> With that Short date highlighted enter dddd, M/d/yyyy to replace the format you have (notice the space after the comma and before M). Click Apply and OK at the bottom of the box. The change is immediate and you should see the new format the Task bar.
> Press Apply and OK for the Region box and it will close.
> Close the Clock & Region and Date & Time Settings windows.

Try this for a while and see if the problem happens again. Let us know what happens. There is a lot more we can do if this doesn't fix the problem.