In Germany there is a certain limit of age for some films, i.e. the films are recommened (or even ordered) to be shown to people above a certain age (6, 12, 16, 18). So if they are beyond the watershed they are called "nicht jugendfrei" in German.
This is a very easy and understandble explanation, but I am afraight, it does not really answer the question for the time when it is shon.

What a SWEET spelling mistake: 'sheen', 'shawn', 'shon' . . . ;:-))

(Do you speak Cantonese ? )

A related question... how would you translate the verb 'to show' in the sense of a TV show being broadcast?

Die Sendung/der Film läuft um 22:00 Uhr auf RTL5.

Sendungen die nicht jugendfrei sind, dürfen erst nach 23:00 Uhr
ausgestrahlt werden.

Actually I am not sure about the time. But there is a watershed in German TV also. I think that movies which are rated FSK16 (suited for 16 and above) have to be shown past 11 pm.
Movies which are FKS18 can not be shown in free TV.

Thanks offliner, that's great. :)

FSK 16 past 10 pm
FSK 18 past 11 pm (with some limitations)

"The watershed is between 10:00pm and 5:30am"

I've just come across the same problem today - I'm looking for a German word for "watershed" in connection with TV broadcasts. There doesn't really seem to be one. Is "zulässige Sendezeit", which I found in the link Jochen Allig provided, the closest we can get?

man könnte vielleicht auch allgemein sagen, daß nicht jugendfreie Sendungen gewissen "Sendebeschränkungen" unterliegen. Eine direkte Übersetzung ist wohl schwer..

As far as I know the 'watershed' in the UK is 9pm. There is no such fixed equivalent in Germany.

More information can be found here: http://de.wikipedia.org/wiki/Altersfreigabe

The German "FSK" (it could be compared to the British BBFC)releases film or movie ratings. These binding ratings come along with certain obligatory broadcasting times:

Films with a "U"-or "PG"-rating may be broadcast at any time.
Films with a rating of "suitable for 6 years or older" may be broadcast at any time.
Films with a rating of "suitable for 12 years or older" may be broadcast from 8 p.m. on.
Films with a rating of "suitable for 16 years or older" may be broadcast from 10 p.m. on.
Films with a rating of "suitable for 18 years or older" may be broadcast from 11 p.m. on.

There doesn't appear to be a special German term for "watershed" since there is more than one regulation for age-rating and broadcasting time.

The correct term in German law is "Sendezeitbeschränkung". E.g. the state treaty on the protection of minors (Jugendmedienschutzstaatsvertrag; JMStV) in the media provides that 16+ content may be shown after 11pm (cf. Section 5 (4) JMStV).