Essential Information

Royal Observatory

17 Oct 2019

Getting up ‘at the crack of dawn’ is not something enjoyed by many, but for some religions, dawn has a much larger significance. 

What is dawn? 

Dawn marks the transition from night to day, as the twilight morning gives way to sunrise. 

What time is dawn? 

Scientists have split twilight into three types depending on how many degrees the Sun is below the horizon. 

Astronomical twilight

In the morning, astronomical twilight begins when the Sun’s centre is 18 degrees below the horizon. 

Nautical twilight

Nautical twilight starts when the Sun’s centre is 12 degrees below the horizon. 

Civil twilight

Civil twilight begins when the Sun’s centre is at six degrees below the horizon.

Dawn during Ramadan

For Muslims during Ramadan, dawn is the time from which they can no longer eat or drink, until the sun sets. This is known as fasting. 

Many Ramadan timetables differ because cities and towns lie on different latitudes and longitudes. This means that even in the same country, dawn and evening twilight times can vary from place to place. 

There can also be different rulings on the definition of dawn and twilight. 

The definition of the true dawn in the Koran is very clear but applying this to a specific time of the day is more difficult. 

What is False Dawn? 

False Dawn, or Zodiacal lights, occurs when the sun reflects off of space particles. This appears in the sky like a triangle of light above the horizon.