Time columns
By default, the smallest unit of measure for a time value is seconds, but you can instead use microseconds with the [microseconds] option.
You can specify microseconds with the [microseconds] option, though the unit of measure for a time value is seconds. The following are examples of time field definitions:
record (tField1:time; ) // single time field in seconds
record (tField2:time[microseconds];)// time field in //microseconds
record (tField3[]:time; ) // variable-length time vector
record (tField4:nullable time;) // nullable time