Uhhh could you give us the plain text version of the funky looking date? (Get that by start editing that funky item and copy paste the content)
I tried inserting date the normal way and it’s working fine. How did you insert this date? 
It happens to all dates. Enter with the selector or using markdown. Example !(2017-11-22 01:00)
It seemed to happen after I was messing about trying a load of dynalist keyboard shortcuts on Safari on the mac. I press control Z a bunch of time and the contents of my list disappeared. I zoomed out and it came back but this date issue seems to be since then.
Now it affects all my docs on any device, app or browser 
Ah I see! Somehow the setting for my date display format had that crazy bit of text entered. I removed it and we are back to normal now. Not sure how that got there though.
Weird, maybe some copy paste accident?
Happy to know the cause of the issue though. Marking it as completed!