Ch.RowBinary.encoding_types/1 currently rejects DateTime and DateTime64 values with non-UTC timezone annotations:

Ch.RowBinary.encoding_types([{:datetime, "Europe/Vienna"}])
# ** (ArgumentError) can't encode DateTime with non-UTC timezone: "Europe/Vienna"

Ch.RowBinary.encoding_types([{:datetime64, 3, "Europe/Vienna"}])
# ** (ArgumentError) can't encode DateTime64 with non-UTC timezone: "Europe/Vienna"

These should be supported. The encoder should either correctly normalize values for the annotated timezone or otherwise handle ClickHouse timezone-qualified DateTime / DateTime64 types consistently with decoding.

Related PR coverage currently locks in the existing behavior so it is visible until this is implemented.