This is the 14050th most frequent German word.
geltend
Valid, applicable, or in force.
Here, 'geltend' is used to indicate that the law is becoming effective or valid.
Das Gesetz tritt morgen geltend.
The law will come into force tomorrow.
In this context, 'geltend' is part of the phrase 'geltend machen,' meaning to exercise rights or make claims effective.
Er machte seine Ansprüche geltend.
He asserted his claims.
Here 'geltenden' is an adjective describing the current rules that are valid or in force.