Volume 2 Chapter 7 Numeric Sub-menu *MDATE

Function

*MDATE is used to test for entries having a specified value or range of values of the modification date.

CSD Contents

When a new entry is archived to the CSD the date of archiving is recorded in two fields:

the accession date
the modification date

When an old entry is edited and re-archived to the CSD the date of re-archiving is recorded in the modification date field.

Both accession and modification dates have the same form :

yyyymmdd where

yyyy is the year
mm is the month
dd is the day

If the modification date equals the accession date then the entry has not been modified (edited) since it was first archived to the CSD.

If the modification date is greater than the accesssion date then the entry has been modified (edited) since it was first archived to the CSD.

The accession/modification date system was introduced in December 1971. All entries added to the CSD prior to that date have accession date 19711231.

Each update of the CSD contains new entries and modified entries. The latter replace old entries which have been edited.

Graphics QUEST3D Procedure

Select *MDATE from the NUMERIC sub-menu and respond to the standard numeric prompts.

Basic QUEST Procedure

Ex.

T1 *ADAT .LE. 19880324
T2 *MDAT .GT. 19880324
QUES T1 .AND. T2

This will register hits for all entries which have accession date less than or equal to 24 March 1988 and modification date greater than 24 March 1988

ie. entries which were first archived to the CSD up to 24 March 1988 and which have been modified (edited) since that date.

Note

The format of *MDATE was changed from 6 digits to 8 in October 1998, as part of the Cambridge Crystallographic Data Centre's preparations for the Year 2000.

Related Keywords

*ADATE

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Volume 2 Chapter 7 Numeric Sub-menu *METRICCLASS .