Time is how we reference change; it is both the dimension of change (e.g. ‘per hour’) and the collective ‘flow’ of change (a non-specific collective like Traffic is to vehicles).
One word, two distinct contexts, both referencing change and change-events.
Dimensions and collective nouns are both abstract nouns. Abstract nouns only exist in our collective minds (some say ‘illusion’, I wouldn’t call Traffic an illusion).
The tangible underlying reality is change and change-events. Zillions of quantum and compund change-events. From the universe expanding, earth spinning, your heart beating , atoms vibrating to quarks decaying – change (of which motion, spatial change, is one subset).
So Time is abstract, change is real.
And change is reference-frame specific (not universal as people misunderstand Time to be).
What is Time? 