Google BigQuery: Calculating Time difference in Minute and Hours

Assume you have a date column "OrderedDate", then we can calculate the total difference in minute and hour with respect to current date time:

SELECT
(CURRENT_TIMESTAMP() - TIMESTAMP_TO_USEC(OrderedDate)) / 1000000/ 3600 AS Diff_Hour,
 (CURRENT_TIMESTAMP() - TIMESTAMP_TO_USEC(OrderedDate)) / 1000000/ 60 AS Diff_Minute
FROM [Project:Dataset.Table]