HOUR/MINUTE/SECOND(t) 

HOUR(t), MINUTE(t), and SECOND(t) are functions (extraction) that extract the hours, minutes, or seconds from the specified time value or timestamp value.

Value t: when used in a function, the expression t must supply a time value, a time stamp value, or an alphanumeric value that matches the current time or time stamp format.

	Result of the Function
HOUR(t), MINUTE(t) or SECOND(t)	Numeric value (hours, minutes, and seconds)
t is NULL value	NULL value