Phase end time is not changeable

Hi there, im currently an administrator of a competition with 90 participants (https://www.codabench.org/competitions/3583/) and we are having problems changing the end time of our competition phase called "Fase 1: Tablero preliminar". We need to set the end time to October 2 03:00 GMT-0 or 00:00 GMT-3 but when trying the GUI only permits to set a Date, setting automatically the end time to October 2 00:00 GMT-0 or October 1 21:00 GMT-3. In Chile, the country the competition is running on, this means that competitors have 3 less hours to make submissions.

Also as presented in #1155 (closed), we also want to create a instantly following phase but it seemes like is impossible. This is less urgent.

Is there a way that you guys can help us setting the end time of our competition phase (with id=6193) to 03:00 GMT-0? We need to fix this urgently as our competition rules stipulate that end time.