If someone talks about the day of reckoning, they mean a day or time in the future when people will be forced to deal with an unpleasant situation which they have avoided until now.
The day of reckoning is coming for the water company directors.
day of reckoning in British English
noun
a time when the effects of one's past mistakes or misdeeds catch up with one
Examples of 'day of reckoning' in a sentence
day of reckoning
There will be another day of reckoning in one year when some of the discarded experiments will come back round, like a pernicious virus.