Rosh Hashanah 2017: When is it, and what does it celebrate?

What do honey, fish and hollowed out rams horns have in common? They are all integral parts of Jewish New Year, otherwise known as Rosh Hashanah, which starts on 20 September and ends two days later.

Literally meaning "the head of the year" in Hebrew, Rosh Hashanah is usually celebrated in September, although its exact date moves every year as the Jewish calendar is based on the lunar cycle. Last year it began on 2 October.

The length of celebrations vary; Orthodox Jews in the diaspora observe the festival for two days, while it's only one day for other denominations, but the theme of the day is the same for everyone: judgement.

The festival marks the first day of the 10 days of repentance, where Jewish people repent for their sins of the previous year and are judged for their sins by god. Those 10 days end with Yom Kippur, literally meaning the day of repentance and the holiest Jewish holiday. They are supposed to be spent thinking and reflecting on your own behaviour, as well as apologising to those you have hurt over the past year.

As with the Sabbath, Orthodox Jews are not allowed to use electricity or work during Rosh Hashanah, which helps with the reflection element, although the rules are slightly more lax when it comes to carrying. Like with many Jewish holidays, it’s essentially an excuse to get together with your family and gorge on delicious food.

On Rosh Hashanah it is traditional to eat honey, usually in cake form, or by dipping an apple in it, which signifies a sweet new year as well as fish heads, to symbolise the head of the year. Jewish people often also eat pomegranates, which are said to have 613 seeds: one for each of the 613 commandments they keep.

Aside from eating, much of both days is spent at synagogue. A hollowed-out ram's horn, known as a shofar, is blown during services, which sounds like this. It’s customary to hear it 100 times over the festival and it symbolises a call to repentance. Many Ashkenazi Jews also observe a tradition called tashlich, meaning "casting off" in Hebrew, on the first day of Rosh Hashanah, whereby they go to a river or nearby body of water and throw pieces of bread in it, which signifies the washing away of sin.