Date and time formats

When the HCL OneDB™ product reads a string that contains time data, it uses the display format to determine how to convert this string to the internal integer value for a DATETIME column.

When the HCL OneDB product prints a string that contains time data, it uses the time display format to determine how to format the internal integer value for a DATETIME column as a string. In the same way, HCL OneDB products use the date display format to read and print strings for the internal values of the date data types.

Important: Display formats specify how client applications view data, but do not affect the internal format of DATETIME or DATE values stored in the database.

The display formats for date and time can include the names and abbreviations for days of the week and months of the year, and the commonly used representations for dates, time (12-hour and 24-hour), and DATETIME values.

Display formats can include names of eras (as in the Japanese Imperial date system) and non-Gregorian calendars (such as the Arabic lunar calendar).

Japanese Imperial-era dates are tied to the reign of the Japanese emperors. The following table shows Julian and Japanese era dates. It shows the Japanese era format in full, with abstract multibyte characters for the Japanese characters, and in an abbreviated form that uses romanized characters (gengo). The abbreviated form of the era uses the first letter of the English name for the Japanese era. For example, H represents the Heisei era.


Gregorian date	Abstract Japanese era (in full)	Japanese era (gengo)
1868/09/08	A¹A²B¹B²01/09/08	M01/09/08
1912/07/30	A¹A²B¹B²45/07/30	M45/07/30
1912/07/31	A¹A²B¹B²01/07/31	T01/07/31
1926/12/25	A¹A²B¹B²15/12/25	T15/12/25
1926/12/26	A¹A²B¹B²01/12/26	S01/12/26
1989/01/07	A¹A²B¹B²64/01/07	S64/01/07
1989/01/08	A¹A²B¹B²01/01/08	H01/01/08
1995/01/01	A¹A²B¹B²07/01/01	H07/01/01

Here A¹A² and B¹B² represent multibyte Japanese characters. For more information, see Customize date and time display formats.