time unit vs amount

time unit and amount both are nouns.

Word	Noun	Adjective	Verb	Adverb
time unit	Yes	No	No	No
amount	Yes	No	Yes	No

As nouns, amount is a hypernym of time unit; that is, amount is a word with a broader meaning than time unit:

time unit: a unit for measuring time periods
amount: how much there is or how many there are of something that you can quantify

Other hypernyms of time unit include measure, quantity.

time unit (noun)	amount (noun)
a unit for measuring time periods	how much there is or how many there are of something that you can quantify
	the relative magnitude of something with reference to a criterion
	a quantity obtained by the addition of a group of numbers
	a quantity of money

time unit (verb)	amount (verb)
	to measure up to in kind or quality
	add up in number or quantity
	be tantamount or equivalent to