i read from another note that
Cuando + the present subjunctive vs Cuando + the present indicative in Spanish
It states that we use cuando+present subjunctive for future events.
But in this notes, it says we need to use cuando+past subjunctive.
Dijo que me llamaría cuando llegara al hotel. (past subjunctive)
= dijo que me llamaría cuando llegue al hotel (present subjunctive)
Are both the same? what is the difference that we choose one over another?