The following rules apply to all functions unless explicitly indicated otherwise in the function description:
For functions that accept numeric types, if one operand is a floating point operand and the other operand is another numeric type, both operands are converted to FLOAT64 before the function is evaluated.
If an operand is NULL, the result is NULL, with the exception of the IS operator.
For functions that are time zone sensitive (as indicated in the function description), the default time zone, UTC, is used if a time zone is not specified.