Welcome to OpenStreetMap and many thanks for adding this.

It might be better to tag it as following, although most pedestrian routing software is unlikely to be aware of it before the 9th.

bridge:structure=floating
bridge=yes
description=Silverworks Island Temporary Bridge, in place on the 1st, 2nd and 9th July 2023 .
foot:conditional=yes @ (2023 Jul 01-02 12:00-17:00; 2023 Jul 09 12:00-17:00)
foot=no
highway=footway
layer=1
name=Silverworks Island Temporary Bridge
seamark:bridge:category=pontoon
seamark:type=bridge

I'm happy to add these, if you have no objections.