The time field data type is defined by the standard input format of hh:mm:ss, using a 24-hour clock. Character representations of other time formats shown in the following table are permitted in SQL commands. Note that when included in SQL commands, these special time formats must be enclosed in quotes. When the XDB Server encounters a string in a location where it expects a time, it determines which of the formats is being used, and performs the internal conversion required. Time requires 3 bytes of storage. If a time field is specified as NOT NULL WITH DEFAULT, null values will be replaced by the current time.