Command Reference Guide > Command Reference Guide > Using Ingres Commands > zic Command--Customize Time Zone Table Files
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zic Command--Customize Time Zone Table Files
Permission required: Access to the directory where the utility is located.
The zic utility customizes time zone table files so you can tailor time zone information for special cases not covered by the IANA or Ingres supplied time zone selections.
This utility works similarly to the UNIX zic utility.
The default timezone_rule_file is indicated by II_TIMEZONE_NAME variable. When II_TIMEZONE_NAME is set to the name of a time zone table, utilities such as date, and C functions such as localtime() and gettimeofday(), make GMT adjustments using the time zone table.
The Olsen time zone table for making Greenwich Mean Time (GMT) adjustments is supported. This method builds time zone tables based on the given rule file. The time zone tables consist of start and end GMT times for each time period. In addition, the corresponding GMT offset value and the abbreviation of the time zone name for each period are kept in the table.
When retrieving internal dates, which are stored in GMT, Ingres searches for the correct time period, and then applies the corresponding GMT offset value and the abbreviated time zone name to determine the local time.
The zic command has the following format:
zic [-v] [--version] [-doutput_directory] timezone_rule_file
-v
Displays additional runtime information.
--version
Displays version ID.
-doutput_directory
Directs the output to the specified directory.
timezone_rule_file
Specifies the name of time zone rule file to customize.
 
Last modified date: 01/30/2023