People have different sleep durations, simplified the older the shorter, whereas between 20 and 65 years of age there is not much change. The sleep can be split into several phases a day. For adults, 7 to 9 hours on average are normal, 6 or 10 hours can also be ok. Here, everybody has to find the individual value for the sleep requirement. Not enough sleep is rather harmful than too much.
Here you can enter the times of up to four sleep phases of a day and calculate the total sleep time. This doesn't mean that it is advisable to split the daily sleep into four phases. Please enter the time in the 24-h-format, e.g. 22:15 to 6:15.