It is very important to keep an eye on and control the duration of a power nap so that your night's sleep is not affected. Optimally, a nap should last a maximum of 20 minutes. This guarantees you to benefit from the positive effects. These include increasing creativity and concentration, combating acute fatigue and reducing tension and stress. Another important argument for a limited sleep duration is related to the different sleep phases. Those who sleep longer than 20 minutes run the risk of entering into the deep sleep phase, from which it is difficult to wake up quickly [1].

For most people, the best time to take a power nap is either right before lunch or shortly after. During this time, we usually feel sleepy and less able to perform [2].

Dream recall is a very complex phenomenon. Why exactly we remember dreams well or not is not yet fully understood. A fundamental problem of science is that dreams can only be 

 be studied in the waking state. It is known that women on average remember their dreams more often than men and that keeping a dream diary can increase the recall rate. Every morning, immediately after waking up, the dream contents should be written down in order to train the ability to remember. Ideally, there should be as few disturbances as possible between waking and writing, so that the attention remains on the dream content. [1] 

What do I have to do? 

Summertime changeover:

During the night, the clocks are set forward from 2 o'clock to 3 o'clock. This marks the end of winter time. 

Winter time changeover:

During the night, the clocks are set back to 2 o'clock at 3 o'clock. This is the end of daylight saving time.

What does this mean for my day? 

Summertime changeover:

The change of clocks result in a night that is now one hour shorter. 

During the day, the consequence is that it gets light earlier in the morning and darker earlier in the evening.

Winter time changeover:

People gain an hour and experience the hour from 2am to 3am twice. [1] 

How can I remember what to do at which time change?

In summer, the chairs of a restaurant are put in front of the house - so the clock is also put forward one hour. In winter, you bring them back inside and thus set the clocks back one hour.

If in doubt, check your smartphone, as it usually adjusts automatically to the respective time.

When will the clocks change back to winter time? 

A reminder on 30 October 2022 in your calendar can ensure that you don't miss the next time change.

Why are the clocks changed at all?

Originally, the aim of the time change was to make better use of the day's brightness in order to save energy. The assumption was that by shifting the time in the summer, people would use less electricity for light in the evening. Problematically, however, more heating is needed in the mornings in autumn and spring. Thus, the energy savings from spring are cancelled out and the result is that hardly any energy is saved. 

For this reason, there are many debates about the usefulness and possible abolition of the time change. 

The internal clock that a person follows is oriented towards daylight. Our sleep-wake rhythm is regulated by hormones that are produced more or less depending on the light conditions. You can find out more about the sleep hormone melatonin here. 

Due to the shifted hour and different light-dark conditions after the changeover to daylight saving time, our inner clock gets out of balance. Among other things, tiredness, sleepiness, and concentration problems can occur. It is therefore important to be aware of the change and the resulting missing or added hour and to prepare for it [1].

To avoid endangering your own health, it makes sense to prepare for the time change before it happens.

• Going to bed earlier in stages to make up for the missing hour at night can help the body adjust and avoid a sleep deficit. It is recommended that you gradually move your bedtime forward in the week before the changeover. In order to be able to go to bed 15-20 minutes earlier every day, try to adjust your daily routine. 
• It is important to sleep well the nights before the time change so that you do not start the following days with a sleep deficit. Learn more about tips and tricks that can improve your sleep quality.
• It's best to change your clocks the night before the time change. This way you can start the day undisturbed and avoid unnecessary timing mishaps. [1]

Extra tips for the next few days:

In the first few mornings after the time change, you can take advantage of the influence of daylight on your sleep-wake rhythm. The bright light helps you set your "inner clock" by suppressing the production of the sleep hormone melatonin. 

In the evening, however, you should slowly avoid daylight by, for example, darkening the room before going to bed. Darkness signals to the body that it is time to sleep.

Even if it is "only" one hour, the potential health effects of the time change should not be underestimated. If possible, don't schedule important appointments or tasks early in the morning and give your body time to adjust to the new clock. [2]