Here's some food for thought.
Adjectival clauses can begin with selected subordinating conjunctions:
when - to describe a time
Ex: Spring is the season when flowers will bloom.
Main clause: Spring is the season
Adjectival clause describing season: when flowers will bloom
Alternative version: Spring is (a time) when flowers will bloom.
Ex: Saturday is (the day) when I will have to fix the faucet.
What do you think?
Student or Learner