It’s just as you say.
Let me explain…
The ONLY empirical evidence of Time is change / change events (look around you – earth spinning, you breathing, quarks decaying – all change event series).
Time represents TWO distinct contexts of change:
1.The dimension of change, i.e. an abstract framework composed of standard units that allow us to calibrate and index change and events. i.e. Time is to change what temperature is to heat, a dimension/calibration set. Temperature is abstract, heat is real, Time is abstract, change is real; and
2. Time is the collective ‘flow’ of change. Time is to change-events what ‘River’ is to water molecules – a collective term. But, fundamentally the word River is an abstract collective of water molecules which are real. Time is a collective abstract, a collective of change-events, which are real – Time, the ‘flow’ of change.
Time, one word, two distinct meaning, both reference change.
And both are abstracts…Time is made up by humans, as you say.