Time Period Format Validation

The Registry will validate observation time periods for consistency with the series frequency value in the FREQ dimension.

This check is not performed if the DSD has no FREQ dimension.

Default frequencies and their corresponding valid time period formats are set out in the following table:

Format	Frequency Code	Example Usage
Yearly	A	2001
Half-Of-Year	S	2001-S1
Third-Of-Year	T	2001-T3
Quarter-Of-Year	Q	2001-Q4
Month	M	2001-12
Week	W	2001-W52
Date	D	2001-12-31
Hour	H	2001-12-31T23
Date Time	I	2001-12-31T23:59:59

Using 'H' for half-year (semiannual)

At ESCB level SDMX data exchanges, there is an agreement to use ‘H’ as the frequency value for semiannual observations with ‘YYYY-S1’ for TIME_PERIOD format.

The Registry supports this by setting 'alternate half year' mode under which:

• Frequency value H means half-year (semiannual or semester)
• The hourly frequency is not supported
• 'YYYY-S1' and 'YYYY-H1' are valid TIME_PERIOD formats for half-yearly observations, however time periods are standardised to ‘YYYY-S1’ on conversion (e.g. such as when converting data in Excel to SDMX 2.1 structure specific)

Alternate half year mode is controlled at system level on Registry start-up by setting the Java System variable “TF_ALTERNATE_HALF_YEAR” to “true”.

If using Apache Tomcat, JAVA_OPTS can be set in the setenv.bat or setenv.sh file:

 SET JAVA_OPTS=-DTF_ALTERNATE_HALF_YEAR=true
 (For Windows systems)

 export JAVA_OPTS=-DTF_ALTERNATE_HALF_YEAR=true
 (For Unix systems)

Different procedures may be required for other web application servers like JBoss.

The Fusion Registry system log will report the following message:

 2021-12-31 23:59:59.123 INFO main io.sdmx.core.fmr.application.FusionRegistryApplicationInitialiser - Using 'Alternate Half-Year' Setting

Active system properties can also be queried using the REST API here.