Function timestamp_time_part 

fn timestamp_time_part<T: ArrowTimestampType>(
    array: &PrimitiveArray<T>,
    part: DatePart,
) -> Option<Int32Array>

Extracts a time-of-day part from a timestamp array without a timezone using integer arithmetic. Returns None for parts that require a calendar conversion.

div_euclid rounds toward negative infinity and rem_euclid yields a nonnegative remainder, so pre-epoch values produce in-range components: -1 ms is 1969-12-31 23:59:59.999, whose second is 59 and millisecond is 999.