Format for Period Fields
Period fields have been added so that you can enter a wide range of date formats. This is useful for any field where you may want to enter a date range or an approximate date. These fields are controlled by a date "parser" (similar to a type of converter) to allow sophisticated date range searching.
Various basic elements can be used to describe a period. They can be used either singularly or combined to build up a date or date range.
Table of Elements
Elements that make up formats valid for period fields:
Examples
|
century1 |
A number divisible by 100 followed by 's' or the word 'century', which may be abbreviated to 'cent.' or 'cent'. Text will not be case sensitive. |
1900s, 1800s |
|
decade2 |
A number divisible by 10 followed by 's' |
1910s, 720s |
|
month |
Jan-Dec, or January-December |
Jan, Feb, Jul, Sep, December |
|
year |
A four-digit number (other than a century or a decade) |
1910 |
|
number |
A number (other than a century, decade or year) |
|
|
ordinal |
A number expressed as a word or a number with a -st, -nd, -rd, -th suffix3 |
Eleventh, 11th |
|
no date |
'n.d.', 'undated' or 'unknown' |
|
| present | The word 'present'4 | |
| season5 | Spring, Summer, Autumn, Fall, Winter | Spring 1918, WINTER 1963 |
| law terms6 | Michaelmas, Hilary, Easter, Trinity |
1 A century is defined as *00-*99, for example, 1900-1999.
2 A decade is defined as *0-*9, for example, 1910-1919.
3 The ordinal element must be used with both parts of a range. 15th-27th Jan 1987 is acceptable, but not 15-27th Jan 1987.
4 When the word 'present' is entered, this is parsed and stored as today's date. When a re-index takes place this field will be stored as the date of the re-index. The word 'present' will continue to be displayed in the field.
5 Spring is interpreted as March-May, Summer is interpreted as June-August, Autumn or Fall is interpreted as September-November and Winter is interpreted as December-February. Text is not case sensitive. Use no punctuation.
6Michaelmas is interpreted as October-November, Hilary is interpreted as January-February, Easter is interpreted as April-May and Trinity is interpreted as June-July. Text is not case sensitive. Use no punctuation.
Table of Qualifiers
The following qualifiers may be added to a date range:
|
pre |
= up to 10 years before |
|
post |
= up to 10 years after |
|
mid, mid., middle (of a century) |
= *30 to *69 for example, 1930-1969 |
|
early (of a century) |
= *00 to *39 for example, 1900-1939 |
|
late (of a century) |
= *60 to *99 for example, 1960-1999 |
|
about |
= the year and 10 years either side |
|
approx |
|
|
between |
|
|
c, c., circ, circ., circa |
= the year and 10 years either side |
|
fl, fl., floruit |
|
|
a.d., ad, A.D., AD, b.c., bc, B.C., BC |
|
|
[gaps],[GAPS],[Gaps] |
for example,
1920 – 1975 [gaps] |
Dates in a range may be separated with one of the following qualifiers:
-
to
-
x
These qualifiers
are treated in the same way as a range when searching period fields.
For
example:
Searching for 8th January 1999 will find a record containing:
‘1st January 1999 x 12 January 1999’ in its Date field
Searching for ‘early 20th century’ will find a record containing:
‘29th December 1910 to 1st January 1911’ in its Date field.
Table of Valid Formats
Valid date formats
are:
Examples
| century | 1900s |
| century century | 1800s-1900s |
| decade | 1910s |
| decade decade | 1910s-1920s |
| month month year | Jan-May 1999 |
| month year | April 1456 |
| month year month year | January 1256-February 2002 |
| month year number month year | Jan 1689-23 December 2001 |
| month year ordinal month year | Jan 1689-23rd December 2001 |
| number century | late 13 century |
| number number year | 12/6/1278 |
| number number year number number year | 13/01/1245-23/08/1678 |
| number month number month year | 12 Dec-16 dec 1435 |
| number month year | 15 Jul 1678 |
| number month number month year | 13 Jun-15 December 1778 |
| number month year | 13 Aug 1787 |
| number month year month year | 14 Sep 1357-Jan 1367 |
| number month year number month year | 23 Apr 1278-28 Feb 1456 |
| number month year year | 23 Jan 1300-1301 |
| number number century | 12-13 century |
| number number month year | 23-27 Jan 1987 |
| year month number | 1974 Nov 30 |
| ordinal century | early 12th century |
| ordinal century ordinal century | 12th century-mid 20th century |
| ordinal month ordinal month year | 29th Oct-30th Oct 2002 |
| ordinal month year | 10th Dec 2002 A.D. |
| ordinal month year number month year | 11th Jan 1899-12 Dec 1999 |
| ordinal month year ordinal month year | 23rd Dec 1233-23rd Mar 1733 |
| ordinal month year year | 13th Jul 1456-1789 |
| ordinal number year | 23rd 12 1899 |
| ordinal number year ordinal number year | 23rd 12 1899-13th 2 1999 |
| ordinal ordinal century | 12th-16th cent. |
| ordinal ordinal month year | 12th-13th Dec 1678 |
| year | 1456 |
| year month | 1974 Nov |
| year month month | 1974 Nov - Dec |
| year month month number | 1982 Sep - Nov 01 |
| year month year month | 1974 Nov – 1975 Dec |
| year month year month number | 1974 Nov – 1975 Dec 31 |
| year month number month | 1974 Nov 01 - Dec |
| year month number month number | 1974 Nov 01 – Dec 31 |
| year month number number | 1974 Nov 01 - 30 |
| year month number year | 1970 Mar 01 - 1990 |
| year month number year month number | 1974 Nov 01 – 1975 Dec 31 |
| year year month | 1974 – 1975 Nov |
| year year month number | 1974 – 1975 Nov 30 |
| year ordinal century | 1256-15th century |
| ordinal century year | 16th century-1704 |
| year year | 1789-1867 |
| season year | Spring 1918 |
| season year season year | Spring 1918-Summer 1920 |
| law term year | Easter 1916 |
| law term year law term year | Hilary 1966-Trinity 1974 |