One could argue that being able to front the following ‘indefinite’ time phrases shows evidence of a higher CEFR level.
A search in iWeb corpus for:
. _II _NNT2 ,
1 . AT TIMES, 11672 C1 → C2
She still misses him at times,
Kit accused me of only being along for the ride
I wished he‘d fall in the river and drown,
2 . WITHIN MINUTES, 1579 B1 → B2
*EVP within = before a particular period of time has finished
Early reports from the scene indicate at least six dead,
many more injured,
with victims being evacuated to local hospitals
within minutes of the explosion.
New York and Moscow will cease to exist.
3 . ON WEEKENDS, 1059
4 . WITHIN DAYS, 915
they were working around the clock.
5 . WITHIN SECONDS, 902
6 . WITHIN HOURS, 649
7 . WITHIN WEEKS, 542
8 . WITHIN MONTHS, 542
9 . IN SECONDS, 326
10 . IN MINUTES, 227
11 . ON WEEKDAYS, 211