If you enter a person into your TNG database, you must have some sort of evidence that they existed and should enter at least a birthdate, and a death date if your know they are no longer alive. No matter how uncertain you are of those dates, date modifiers allow you to frame the boundaries of your uncertainty.
Internally, TNG keeps dates in 50 character strings, allowing for date 'modifiers'.
(For date and date modifier abbreviations in German see Inputting Dates - Eingabemoeglichkeiten)
Upper / Lower Case in Dates
When displaying event dates TNG leaves the letters in the case in which you originally entered them, but always converts the letters to all capitals when performing internal calculations.
If you are sure an event occurred, are not sure of the exact date, but are sure of the range of dates, you may supply the known range by enclosing dates using BET date AND date (for example, BET 1845 AND 1851).
These date modifiers also allow for open-ended dating (for example, FROM 1835).
If the event you are entering occurred during or before 1752 (Britain and North America) or 1582 (Europe) you must be very careful when entering the date; spend some time researching the Gregorian Calendar first.
If you're absolutely unable to estimate a date, but know the event happened, the designers of the GEDCOM standard suggest you use the date modifier Y as explained in the following excerpt:
The meaning of a GEDCOM tag without a value on its line depends on its subordinate context for any assertions intended by the researcher. For example, In an event structure, a subordinate DATE and/or PLACe value imply that an event happened. However, a subordinate NOTE or SOURce context by themselves do not imply that the event took place. For a researcher to indicate that an event took place without knowing a date or a place requires that a Y(es) value be added to the event tag line. Using this convention protects GEDCOM processors which may remove (prune) lines that have no value and also no subordinate lines. A N(o) value must not be used on an event tag line to assert that the event never happened.
GEDCOM Date Modifier Descriptions
excerpted from http: // www. gedcom . net/0g/gedcom55/55gcint.htm (site deleted):
- ABT date
- CAL date
- EST date
- ABT =About, meaning the date is not exact.
- CAL =Calculated mathematically, for example, from an event date and age.
- EST =Estimated based on an algorithm using some other event date.
- ABT 1871
- CAL 21 Sep 1799
- EST Apr 1913
- FROM date
- TO date
- FROM startdate TO enddate
- FROM =Indicates the beginning of a happening or state.
- TO =Indicates the ending of a happening or state.
- From 1904 to 1915 =The state of some attribute existed from 1904 to 1915 inclusive.
- FROM 1904 =The state of the attribute began in 1904 but the end date is unknown.
- TO 1915 =The state ended in 1915 but the begin date is unknown.
- BEF date
- AFT date
- BET startdate AND enddate
- AFT =Event happened after the given date.
- BEF =Event happened before the given date.
Short form Long Form ---------- --------- 1852 BET 1 JAN 1852 AND 31 DEC 1852 1852 BET 1 JAN 1852 AND DEC 1852 1852 BET JAN 1852 AND 31 DEC 1852 1852 BET JAN 1852 AND DEC 1852 JAN 1920 BET 1 JAN 1920 AND 31 JAN 1920
Inputting Dates in Multi-Language Environment
See Inputting Dates - Eingabemoeglichkeiten on guidelines for inputting dates in a multi-language environment.