I think that's the 'other left' (or right) side of the menu...at least it is here. 
Top menu bar of OGR webpage, far right, mouse over your picture, select 'Personal Settings' about half way down the menu. Time zone is the first setting in the resulting list.
Well now that I have found it, nothing seems to be selectable there and I don't see a way to change it? MAybe check your windows 10 settings?
It's your Windows 10 time zone setting on your PC, I just checked and reset mine and it gave me the time zone error. The personal settings menu now has an option to set the time zone, just below the actual setting.
Windows settings, Time & Language, Time zone toward the bottom of page. Also I have 'Set Time Zone automatically' turned off. Not sure it matters, but I have a desktop PC, it's not traveling anywhere and I don't like Windows changing things on me w/o notice.
