Support : Publications : Chronolog Archives : November/December 2004

Searching Multi-Year Date Ranges

The Dialog system has a maximum capacity of 2,000 terms retrievable with the colon (:). If the colon is used to denote a range of dates (e.g., PD=19940101:19950101), the system will consider each date to be a separate term. Therefore, a date range that exceeds about 5.5 years may exceed this maximum (2,000 divided by 365 equals approx. 5.47).

When searching multi-year date ranges, express the whole years using PY=, not PD=:

PY=1990:1998

PD=19900101:19981231

The first method will return the same results while generating fewer DialUnits.

For date ranges beginning and/or ending in mid-year (e.g., June 14, 1991 through October 6, 1996) use the following syntax:

PD=19910614:19911231 OR PY=1992:1995 OR PD=19960101:19961006

Be sure to check the Bluesheet first because not all databases have both PY= and PD=.

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The article "Appropriate Copy for Dialog and Dialog DataStar E-Links Manager" provides more information on Dialog eLinks Manager.

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