Randolph West covers the TIME data type in SQL Server:
This week, we look at the
TIMEdata type. It is formatted asHH:mm:ss.fffffff, whereHHis hours between 0 and 23,mmis minutes between 0 and 59,ssis seconds between 0 and 59, andfrepresents 0 or more fractional seconds, up to a maximum of seven decimal places.With a maximum length of 5 bytes,
TIMEcan store a value with a granularity of up to 100 nanoseconds.
I tend not to use TIME very often.  It’s useful if you need it, but I rarely find myself needing a dateless time.