Analytica 4.0 provides much greater flexibility for formatting dates -- in US and ROW (rest of the world) formats. It also adds four useful functions for computing with dates.
You can control whether and how a number is displayed as a date in the Number Format dialog, available from the Result menu:
The Date format in the Number Format dialog offers these options:
- Short -- e.g. 8/5/2006 (based on Windows Regional Settings)
- Abbrev -- e.g. Aug-5-2006 (based on Windows Regional Settings)
- Long -- e.g. Thursday, 05 August, 2006 (based on Windows Regional Settings)
- Custom -- which lets you select an existing custom format or type in a new one. These are some examples
- dd-MM-yy → 05-8-06
- 'Q'Q YYYY → Q2 2006
- www, d MMM yyyy → Thu, 5 Aug 2006
- wwww, d of MMMM, yyyy → Thursday, 5 of August, 2006
The Custom date format uses these codes:
- d -- numerical day of the month -- 1, 2,... 31
- dd -- numeric day of the month -- 01, 02,...31
- ddd -- abbrev ordinal day of month - 1st, 2nd, ..., 31st
- dddd -- ordinal day of month -- first, second, ..., thirty-first
- Dddd -- capitalized ordinal day of month -- First, Second, ... Thirty-first
- www weekday in three letters -- Mon, Tue,.. Sun
- wwww weekday in full -- as Monday, Tuesday, ... Sunday
- M month as a number -- 1, 2, ... 12
- MM month as two-digit number -- 01, 02, ...12
- MMM month as three letter name -- Jan, Feb, ... Dec
- MMMM month as full name -- January, February, ... December
- q quarter as one digit -- 1, 2, 3, 4
- yy year as two digits -- e.g., 99, 00, 01
- yyyy year as four digits -- e.g., 1999, 2000, 2001
- Any other characters, including space, appear as give in formatted dates.
- To show text that is also a code, enclose it in quotes, e.g. 'q'q → q2
If you specify a date format for an input variable or Edit table, you can enter dates in any acceptable date format -- no matter which date format is specified. For example, with a date format, Analytica will interpret "9/11/2001" as "11 September, 2001" on a computer set to USA region or "9 November, 2001" elsewhere. With no date format, it will interpret it as ((9 divided by 11) divided by 2001)!
Regional and Language settings
The date formats used for Short, Abbrev and Long are based on your regional settings. These are set from the Date tab of the Regional and Language Settings dialog, available from the Windows Control Panel. The formats are a function of your location, so user in the US may see a short date as m/d/yyyy, while a user in Denmark may see dd-mm-yyyy (however, these can be customized). Analytica derives the Abbrev setting from the Windows Long date regional format. The language also controls the names of days and months: For example, if you set the language to Spanish (Argentina), Makedate(2007, 2, 3) with the Long date setting displays as:
- Sábado, 03 de Febrero de 2007.
Date values and the date origin
Analytica represents a date as a date value -- that is, the number of days since the date origin. By default the date origin is Jan 1, 1904 -- as used by most Macintosh applications, including Excel on Macintosh, and all releases of Analytica on Macintosh and Windows up to Analytica 3.1. If you check Use Excel date origin in the Preferences... dialog, the date origin is Jan 1, 1900 -- as used in Excel on Windows (unless reset) and most other Windows software.
With 'Use Excel date origin checked, the numeric value of dates are the same in Analytica and Excel for Windows for dates falling on or after 1 Mar 1900. Because of a bug in Excel, in which Excel incorrectly treats Feb 29, 1900 is a valid day (1900 was not really a leap year), dates falling before that date will not have the same numeric index in Analytica as they do in Excel.
When using models containing dates or date functions from Analytica releases 3.1 or earlier, you should keep Use Excel date origin unchecked. If you want to paste or link values from Excel for Windows or other Windows software to or from Analytica, you should check this option.
Analytica can handle dates from 1 AD to well beyond 9999 AD. Dates earlier than the date origin are represented as negative integers. Dates use the Gregorian calendar: Years divisible by 4 are leap years, except those divisible by 100 which are not leap years, except those divisible by 400 which are leap years.
You can simply add an integer n to a date to get the date n days ahead.
MakeDate(year, month, day)
Gives the date value for the date with that year, month, and day. If omitted, month and day default to 1.
MakeDate(2007,5,15) → 15-May-2007 MakeDate(2000) → 1-Jan-2000
- year, month, and date should be positive integers, or coercible to positive numbers.
- MakeDate(year: Coerce Positive; month, day: Optional Coerce Positive)
- Special functions
Gives the year, month, or day as a number, given a date value date. When part='Y', it gives the four digit year as a number, such as 2006. When part='M', it gives a number between 1 and 12. When part='D', it gives a number between 1 and 31. When part='w', it returns a number from between 1 (Sunday) and 7 (Saturday).
DatePart(MakeDate(2006, 2, 28), 'D') -> 28
- date as a date number, and part as 'Y', 'M', or 'D'(upper- or lowercase).
- DatePart(date: Numeric; part: Text)
- Special functions
- Less Common Options
- part may also be: 'MMM' (returns e.g., 'Jan'), 'MMMM' (e.g., 'January'), 'ddd' (e.g., '1st'), 'dddd' (e.g., 'first'), 'Dddd' (e.g., 'First'), 'w' (e.g., 1 for Sunday, 2 for Monday, ..., 7 for Saturday), 'www' (e.g., 'Mon'), 'wwww' (e.g,. 'Monday'), 'q' (1 to 4, e.g., 1 for Jan-Mar).
- More Examples and Tips
This makes a sequence of weekdays landing between date1 and date2:
Index J:=date1..date2 do Subset( DatePart(J,"w")>=2 and DatePart(J,"w")<=6 )
DateAdd(date, offset, unit)
Gives a date value that is offset years, months, or days from date, according to whether unit is "Y", "M", "D", or "WD".
DateAdd is especially useful for generating sequences of dates for a time index:
DateAdd(MakeDate(2006,1,1), 0..12, "M") -> ["1 Jan 2006", "1 Feb 2006", "1 Mar 2006", ... "1 Jan 2007"]
(note: the actual values in the list returned above are numbers formatted as dates)
If an offset would appear to go past the end of a month, such as
DateAdd( MakeDate(2004, 2, 29), 1, 'Y' ) -> 2005-Feb-28 DateAdd( MakeDate(2006, 10, 31), 1, 'M' ) -> 2006-Nov-30
it returns the last day of the month. In the first example, the date 2005-Feb-29 does not exist, and in the second example the date 2006-Nov-31 doesn't exist, so in each case, the last day of the month is returned.
Adding a day offset, DateAdd(date, n,"D"), is equivalent to date+n, since date is represented as an integer. DateAdd(date,n,"WD") adds the specified number of weekdays to the first weekday equal to or falling after date.
Use a negative offset to subtract units from a date.
- date and offset to be numbers, and unit to be 'Y', 'M', 'D', or 'WD' (upper or lowercase).
- Syntax: DateAdd(date, offset
- Number; unit: Text)
- Special functions
- More examples and tips
MakeDate( 2007, 2, 10) --> Saturday, 2007-Feb-10 DateAdd( MakeDate(2007,2,10), 0, "WD" ) --> Monday, 2007-Feb-12 DateAdd( MakeDate(2007,2,10), -1, "WD" ) --> Friday, 2007-Feb-9 DateAdd( MakeDate(2007,2,10),365, "D" ) --> Sunday, 2008-Feb-10 MakeDate(2007,2,10) + 365 --> Sunday, 2008-Feb-10 DateAdd( MakeDate(2007,2,10),365, "WD" ) --> Monday, 2008-July-7
The following generates a series of dates landing on the 1st and 15st of each month:
var J := 0..24; DateAdd( MakeDate(2006,1, if Mod(J,2)=0 Then 1 Else 15), floor(J/2), "M") --> [ 2006-Jan-1, 2006-Jan-15, 2006-Feb-1, 2006-Feb-15, 2006-Mar-1, ..., 2007-Jan-1 ]
Returns the date number for the day on which the function is evaluated. Unlike other functions, it gives a different value every day the model is run.
- Special functions