Date fields

Date field types are mainly used in calendar databases for entering start and finish dates, though they are available in all types of databases.

Date (min) and date (max)

There are two types of Date fields available, namely Date (Min) and Date (Max). The only difference between them is how upper level values are calculated. For Date (Min) fields, an upper level record will take the minimum date value from all its child records. For Date (Max) fields, an upper level record will take the maximum date value from all its child records. Note that the first child record will not necessarily contain the minimum date value and the last child record will not necessarily contain the maximum date value. An example where this could happen is where a Main database Date field is used to store the date on which mining started. If the blocks are not mined in a regular order, then the dates would be jumbled.

Date display

Date fields can be displayed in a number of ways however the default is d/m/yy h:mm, where d is the day of the month, m is the month, yy is the year (abbreviated to 2 digits), h is the hour in the day (24 hour clock) and mm is the minutes. Click here for more information on changing the display format of a date field.

Date entry

Date fields can have the data entered in a variety of formats. The following general rules apply:

•	The day and the month can be entered as numbers with or without preceding zeros.

•	The month can be entered as the full month name (eg. January) or as the three letter abbreviation of the month (eg. jan).

•	The day month and year can be separated by either a "/", a "-" or a space character.

•	The year may be entered in full (eg. 1998) or abbreviated (eg. 98). If the year is abbreviated, 30 to 99 will be interpreted as 1930 to 1999, while 0 to 29 will be interpreted as 2000 to 2029. To enter a year outside this range (eg. 2030), you must type this in full.

•	The time should be separated from the date by one or more spaces.

•	The hours should precede the minutes

•	The time should include both the hours and the minutes, separated by either a ":" or a "." character. Regardless of which character separates the two numbers, the minutes will be read as minutes, not as decimal hours.