Hi Firefox team,
First of all Cheers and Greetings for bringing up an excellent x-platform browser!
IMHO, a small {permanent} digital clock widget could be placed up top right (within the context window/ tab) depicting HH:MM (UTC) or optionally world clock (configurable upto 2 - 3 locales) with semi-transparent/ translucent feature - visible / non-transparent upon mouse hover etc. [primarily for desktop oriented browsers, where taskbar isn't accessible/ large screens]. Pl. se attached idea (image) for reference.
This will be useful for many users participating in meetings and other important to-do lists. May/ can extend to other Mozilla apps also.
Kindly omit if feat. / widget/ theme is already available with these features incorporated.
Best development!
Abhishek Kalia