CQL Time values are used to represent a time of day, independent of the date. Time value must be known to at least the hour precision, and potentially to the millisecond precision. Time values are specified using at-symbol (@) followed by an ISO-8601 textual representation of the Time value:
@T12:00:00.0Z
@T14:30:14.559-07:00
Note that the Time value literal format is identical to the time value portion of the DateTime literal format.
For Time values, timezone may be specified as either UTC time (Z), or as a timezone offset. If no timezone is specified, the timezone of the evaluation request timestamp is used.
Specifically, because Time values may be specified to varying levels of precisions, operations such as comparison and duration calculation may result in null, rather than the true or false that would result from the same operation involving fully specified values.