Fix for labels on datetime range display.
Issue #2907483 by kurinji selvan: Label for the field does not displayed
Issue #2885475 by Dennis Cohn: Latest library compatibility / composer
Note that you need to update datetimepicker library.
For manually way – download latest library from here https://github.com/xdan/datetimepicker, and put entire extracted folder in libraries (name folder datetimepicker)