Time is a noun, (an abstract noun) because it's a thing. If it were an adjective you could describe someone or something as being 'time' in the same way as you could say 'tall' or 'clever'
Just the word time is a noun, from my learning (but maybe I am stupid)...I don't know how to explain well the English grammar but let me try:
Adjective is used to modifies a noun or other substantive.
Every time you are describing something or someone, you are let's say... "adjectiving" that person or thing.
This is the best I can tell you right now.
time is a noun... it's a thing... it's an abstract idea, but it's still a thing... an adjective is descriptive. what does "time" describe? nothing, because it's not an adjective. timely, timeless, etc would be adjectives.
Time can be alot of things it depends how you use it!
like:
Main Entry: 1time
Pronunciation: 'tIm
Function: noun
Etymology: Middle English, from Old English tIma; akin to Old Norse tImi time, Old English tId -- more at TIDE
1 a : the measured or measurable period during which an action, process, or condition exists or continues : DURATION b : a nonspatial continuum that is measured in terms of events which succeed one another from past through present to future c : LEISURE
time is of the essence; time is a place, time is action, time can describe something and time can modify; so it is a noun, a pro noun,an adjective,a verb, an adverb (with ly(...in a timly manner)) and a proverb
The time is 10pm. (time is a noun and the subject of the sentence.)
What time is it? (again - noun and subject)
I don't have time to do that. (noun - direct object)