Entanglement is easily explained when you realize that there are two types of entities making up reality, and that they experience time in two wildly different ways:

Matter is not able to move exactly at the speed of light. Special Relativity tells us that matter particles always experience some spacetime interval, no matter how tiny. Matter is always tied to its subjective spacetime reference frame. It always observes any phenomenon in the universe as a process, according to its own space and time units.

On the other hand, the massless quanta that create all the field disturbances that matter is able to detect move at the speed of light exactly. Special Relativity, in this case, tells us that no time would elapse for them. They experience zero proper time. So the light-like paths they seem to trace to us are instant events to them. What we picture as phenomena propagating at c from our spacetime reference frame happens all at once in a single blink of existence for them.

Then, you can see that the time "O" for the entanglement event, and the times "A" and "B" for the detection events (regardless of their simultaneity) are experienced as a single "now" by the massless carriers involved, no matter how long or short their null geodesics appear to be from our spacetime frame of reference.

The thermodynamic time you talk about is the way massless quanta experience time (instantaneity of the emission-flight-detection event), while the reference time you talk about is the way matter observers experience time (spacetime interval of the emission-flight-detection process).