Celestial cause of the tide changing at the quarter-year (5)

I believe the answer is:

deity

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'celestial cause of' is the definition.
The definition suggests a singular noun which matches the answer.

'tide changing at the quarter-year' is the wordplay.
'changing' indicates anagramming the letters.
'at' is a charade indicator (letters next to each other).
'the quarter year' becomes 'y' (I am not sure about the 'quarter' bit.).
'tide' is an anagram of 'deit'.
'deit'+'y'='DEITY'

'the' acts as a link.

Can you help me to learn more?

(Other definitions for deity that I've seen before include "Supreme being" , "Divinity" , "Supernatural being" , "God or goddess" , "Refuge" .)

I've seen this clue in the Evening Standard.

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