Would be ace to have this, please 
Use case: When you’re searching for a date, you need to manually type the exact format (i.e. 2020-01-30), whereas simply typing ! and then choosing the date is a sweeter user experience.
Thanks for your consideration!
That would be useful, in addition to the tag autocomplete we have now 
By the way, do you expect !(2020-01-30) to find !(2020-01-30 11:00 am), or do you expect it to be a simple text search, where the date picker is just a shortcut to enter dates?
I was thinking the same behaviour as the existing functionality.
As you know, when you type ! into a bullet, the calendar pop-up displays. If we somehow could have that replicated for search—it’d be great!
I think you’re right that if you did a search for !(2020-01-30), it’d return all dates matching this criterion, regardless of the time. Then, if you wanted to be even more specific, you’d choose a time from the calendar pop-up too!
Do you mean that’s your desired behavior or your current behavior?
The current behavior seems to be that !(2020-04-09) won’t match !(2020-04-09 07:00) , as it’s merely a text search.