Task: Sentence Expansion
Input (English): During this time , it has passed overhead once and underfoot once , so in many places the period of strongest tidal forcing is the above-mentioned , about 12 hours and 25 minutes .
Output (English): During this time , it has passed overhead ( culmination ) once and underfoot once ( at an hour angle of 00:00 and 12:00 respectively ) , so in many places the period of strongest tidal forcing is the above-mentioned , about 12 hours and 25 minutes .