Thanks for implementing this!
I just tested the new Custom Time Range feature.
I have platform timezone set to EET. If I set Date From to 00:00:00.000 19.05.2017, a test starts at 21:00:00.000 19.05.2017 EET, which is not correct. (Please see the attached image)
Otherwise, everything seems to work as it is supposed to.
(If I set platform timezone to UTC, the test starts at the correct time.)