Student or Learner
who to use the expression properly,
"day of reckoning"
"Day of reckoning " means a time when something must be dealt with. It generally has unpleasant connotations to it. It comes from the Biblical day of reckoning ( i.e Judgment Day...when God passes judgment on everyone)
An example of modern day use is " Borrowing more money to pay off your debts will only delay the day of reckoning" .... meaning the time will come when you will have to account for and pay back the money.