We said, “Allah’s Messenger, how long would he stay on the earth?” He (ﷺ) said, “For forty days, one day like a year and one day like a month and one day like a week and the rest of the days would be like your days.” We said, “Allah’s Messenger, would one day’s prayer suffice for the prayers of day equal to one year?” Thereupon he (ﷺ) said, “No, but you must make an estimate of time (and then observe prayer).”