Dates are very important in genealogy, and most editing screens have place for entering date. There are two types of dates that can be entered:
- Date / Time of an event
- Date period for extended period of time.
Date / Time is a single point in time continuum, date period is defined by the beginning and end dates.
If entered correctly, dates are understood by the program, and are used in calculating and displaying data on the time scale. PGV (and GEDCOM standard) are very flexible in how dates can be entered, and account for most cases found in genealogy. If absolutely necessary, date can also be entered as a free form text, but with a loss of functionality.
Date / Time
- One enters the date / time events as DD MMM YYYY: day (as number), month (as abbreviation in English) and year (as number), e.g. 12 Jan 1907. If you are using non-English version, the month will be translated in display, but not in data entry; use English month abbreviation.
- If some part of the date is not known, you can skip it, e.g. Jan 1907 or 1907
- If you are unsure of the information, you can use the approximation: ABT (about), e.g. ABT Jan 1907, or the limits between which the event occurred: BET .. AND (between - and) e.g. BET 1 Jan 1907 AND 20 Mar 1907. One-sided limit of approximation allows you to use BEF (before) and AFT (after), if the event is known to occur before or after some date.
- Less frequently used, but allowed are the details on the approximate date: EST (estimated), CAL (calculated for example from another date and period) and INT (interpreted). In case of INT, you should add the base of the interpretation in the date field. Alternatively you can use ABT and enter the details in the note field. Examples: EST 1907, CAL 1907, INT 1907 (two years before marriage).
PGV displays a calendar as an aid in entering dates. There is a field for time as well; the format is hh:mm (24-hour or 'military' clock).
For events that occurred over a period of time you should use a DATE_PERIOD construct using FROM .. TO. For example FROM 1907 TO 1911 or FROM 15 Jan 1907 TO Dec 1911. If one end of the period is unknown, you can use only FROM or only TO. The rules for approximate dates listed above also apply here.