How does Match-IT display dates?

There are several forms you will see dates in the system:

dd/mm/yy

This is the conventional day, month, year notation. The year is always shown as two digits. The correct century is implied (see later).

ASAP

As Soon As Possible. This is a date that is always today.

TBD

To Be Defined. This is a marker for a date that is required but you don’t know what it is yet.

+N days

N days after today.

-N days

N days before today.

blank

A blank date means the date is not known. It has no value.

How does Match-IT recognise 20xx dates?

The date system operates over a 100 year span. The reference date for this span is always today (whatever that may be). The span is considered to stretch back in time for 80 years and forwards 20 years, relative to today. For example, in 1997, two digit years in the range 17 to 99 are interpreted as 19xx, and years in the range 00 to 16 are interpreted as 20xx.

How does Match-IT store dates internally?

It is important to appreciate that the way dates are shown (as given above) is very different to how they are actually stored internally. Internally they are stored as the number of days that have elapsed since December 28th 1800. The allowable date range for internal computation purposes is January 1st 1801 (day number 4) to December 31st 2099 (day number 109,211).

Does Match-IT use any special ‘marker’ dates?

Match-IT uses day numbers that are negative to have special meaning. When you define a date as ASAP, TBD, or +/-N days, they are stored internally as a negative day number. This makes them easily distinguishable from normal dd/mm/yy dates. The date system automatically distinguishes these types.

How can I verify correct operation for 20xx dates?

You can easily verify the handling of the year 2000 issues using the calendar shown to you on any date field. Just go to any date field and press the associated ellipsis button. A calendar will pop up for the month containing the date. Type in any date you wish to test in the entry field and the calendar will change to show you the month of that date. For example, type in 1/2/0 and you’ll get February 2000, which you’ll see is a leap year.