Excuse me if I'm misunderstanding what you mean … but, no, it really isn't. UTC is defined quite precisely and accurately to track the mean solar time. Time zones are usually designed to balance the zenith of the sun (that's "noon") and regional boundaries (although some countries make some… creative decisions in that regard). "Morning" and "evening" are defined in terms of the position of the sun, not some number on a clock.
That's fair. That's on me.
Excuse me if I'm misunderstanding what you mean … but, no, it really isn't. UTC is defined quite precisely and accurately to track the mean solar time. Time zones are usually designed to balance the zenith of the sun (that's "noon") and regional boundaries (although some countries make some… creative decisions in that regard). "Morning" and "evening" are defined in terms of the position of the sun, not some number on a clock.