The sugested method did not work for me for some reason in Windows 8.1 SL but after trying for 2 or 3 hours I found something out that worked for me. I'm from Brazil and "datemodified" equals "datademodificação" in my language but if you want to use English you can always use system.datemodified instead the equivalent in your language.
This worked in Windows 8.1 SL for me:
system.datemodified:(>YYYY-MM-DD HH:MM .. <YYYY-MM-DD HH:MM)
Ex: To find files modified in 02/28/2017 form 10:50 AM to 10:59 AM (The clock is set to show 24 h):
system.datemodified:(>2017-02-28 10:00 .. <2017-02-28 10:59)
If your clock is set to 12 h you may have to use AM or PM behind the time
Here are some other examples that worked (In Brazil we use DD/MM/YYYY date format):
Datademodificação:>28/02/2017 10:50 .. Datademodificação:<28/02/2017 10:59
Datademodificação:>28/02/2017 10:50 AND Datademodificação:<28/02/2017 10:59
system.datemodified:>28/02/2017 10:50 .. system.datemodified:<28/02/2017 10:59
system.datemodified:>2017-02-28 10:50 .. system.datemodified:<2017-02-28 10:59
It seems to make no differance is you use the date as YYYY-MM-DD or DD/MM/YYYY both worked, what looked like to do the trick for me was using > (bigger than) and < (smaller than) signs.
If you want the "creation date" instead of "modified date" just use: datecreated instead of datemodified.
Greetings, Ricardo Bohner