
A short push of the on/off button puts it into screen lock mode, which another short push is needed to bring it out.

A long push on the on/off button turns the reader all the way off, and another push on the on/off button is needed to bring it back.
When you turn the reader OFF, the clock loses power and resets to factory setting when you turn the reader on.
If you just use the lock mode, or leave the reader on, the clock will continue to work, but not show an updated time until you turn a page. Remember, the eink pages are static, they don't change on their own.
We've all struggled with the clock process.

Also, it is in Day Month Year format, not Month Day Year.
AJ