The cache is NOT at the posted coordinates, but is very nearby. You can work the puzzle any time, but the final container can only be accessed at these times:
Sunday Closed
Monday 10AM–6PM
Tuesday 10AM-6PM
Wednesday 10AM–3PM
Thursday 10AM–6PM
Friday 10AM–6PM
Saturday 10AM–3PM.
Not accessible on Sundays and all state holidays.