The "Reporting Time Units" screen registers and changes reporting time units. A reporting time unit is a breakdown of time-dependent data into a time range. Registering reporting time units is a typical activity for application developers. See the warning under Application Development. The entry fields have the following meaning: - "Code": The code that refers to the reporting time unit. - "Description": The description of the reporting time unit. - "Sort Order": The numeric value that sorts the reporting time units when a list box in a screen shows them. - "Presentation mask": A pattern that describes how to show a date. Each character in the presentation mask describes exactly one character in the presentation. The following characters are possible in the presentation mask: - `YYYY`: the year in four digits. - `MM`: the number of the month in two digits. - `DD`: the number of the day in two digits. - `YY`: the last two digits of the year. - `RR`: the last two digits of the year. The first two digits of the year are determined by the current date of the database server and the digits provided. Four rules apply, as listed below. The four rules for `RR` are: - If the provided year is between 00 and 49 and the current year is between 00 and 49, the century is the same as the current century. For example, if the provided year is 15 and the current year is 2005, the result is 2015. - If the provided year is between 50 and 99 and the current year is between 00 and 49, the century is the current century minus one. For example, if the provided year is 75 and the current year is 2005, the result is 1975. - If the provided year is between 00 and 49 and the current year is between 50 and 99, the century is the current century plus one. For example, if the provided year is 15 and the current year is 2075, the result is 2115. - If the provided year is between 50 and 99 and the current year is between 50 and 99, the century is the same as the current century. For example, if the provided year is 55 and the current year is 2075, the result is 2055. The other characters in the presentation mask are: - `RRRR`: the year in four digits, where the first two digits of the year are determined by the current date on the database server and the digits provided. The four rules for `RR` apply. - `IW`: the week number of the year based on the ISO 8601 standard. - Further characters: see the SQL language reference of Oracle.