What is the difference between greater and larger? For example, should we say for time, the waiting time is greater than or the waiting time is larger than?
Taken literally, "larger" refers to physical size. "Greater" refers to value.
Thus you would say, "An elephant is larger than a mouse". But -- assuming you're talking about size -- you wouldn't say "An elephant is greater than a mouse."
If you want to compare quality, you might say, "Rembrandt's paintings are greater art than Picasso's". If you said they were "larger", that would mean that the piece of canvas was physically bigger, rather than being a comparison of the quality.
Sometimes either one will work. Like if you are comparing two numbers, it is probably better to say "9 is greater than 8". People often say, "9 is larger than 8", but depending on the context, a listener might think you mean that the numeral was drawn taller and wider.
"Larger" is sometimes used metaphorically. Like we might say that one problem is larger than another, meaning it's a more serious problem, not that it necessarily occupies more space.
For a duration of time, we would normally use neither "larger" nor "greater" but "longer" or "shorter": "The wait is shorter on that line." "These batteries last longer."
If you're talking about a particular point in time rather than a duration, you'd normally say "earlier" or "later".
For time you would use greater, while for physical bodies, you would use larger. This is not comprehensive, but it's a direct answer to the second part of your question. If no native speaker replies, I will try to provide a more comprehensive answer.