Up to 6
Time is entered in 24-hour format, such as 181732, and is displayed in 12-hour format, such as 6:17:32 PM. Dexterity automatically checks each time value to ascertain whether it’s within the proper range of a time value.
An uninitialized time field (one that hasn’t been set to a value) will have the value 000000. Dexterity allows this as an acceptable time value.