Answer:
Abstract noun.
Step-by-step explanation:
Abstract nouns are the nouns that express an idea, thought, feeling, quality, etc. as compared to the solid entity if a normal noun. They are abstract, thus, the name abstract noun.
In the given sentence, there are two abstract nouns- "value" and "time". The word "value" express the quality of the noun 'time'. And these two nouns exist only in thought and do not have any physical existence.