I don't know where that interpretation came from but this is referring to a hadith that refers to the coming of the ad-dajjal.
Here's part of the hadith:
We said: Allah's Apostle
, how long will he stay on Earth? He said: For forty days, one day like a year, one day like a month, one day like a week, and the rest of the days will be like your days.
We said: Allah's Apostle
will one day's prayer suffice for the prayers of the day equal to one year?
Thereupon he
said: No, but you must make an estimate of the time (and then observe prayer).
http://muttaqun.com/dajjal.html