.\" This is a wxWidgets manpage page generated from the XML docs .TH wxDateSpan 3wx 2005-02-15 "wxWidgets" "wxWidgets class documentation" .SH NAME wxDateSpan \- A logical time interval. .SH DESCRIPTION This class is a "logical time span" and is useful for implementing program logic for such things as "add one month to the date" which, in general, doesn't mean to add 60*60*24*31 seconds to it, but to take the same date the next month (to understand that this is indeed different consider adding one month to Feb, 15 -- we want to get Mar, 15, of course). When adding a month to the date, all lesser components (days, hours, ...) won't be changed unless the resulting date would be invalid: for example, Jan 31 + 1 month will be Feb 28, not (non existing) Feb 31. Because of this feature, adding and subtracting back again the same wxDateSpan will not , in general give back the original date: Feb 28 - 1 month will be Jan 28, not Jan 31! wxDateSpan objects can be either positive or negative. They may be multiplied by scalars which multiply all deltas by the scalar: i.e. 2*(1 month and 1 day) is 2 months and 2 days. They can be added together and with wxDateTime or wxTimeSpan , but the type of result is different for each case. Beware about weeks: if you specify both weeks and days, the total number of days added will be 7*weeks + days! See also GetTotalDays() function. Equality operators are defined for wxDateSpans. Two datespans are equal if and only if they both give the same target date when added to every source date. Thus wxDateSpan::Months(1) is not equal to wxDateSpan::Days(30), because they don't give the same date when added to 1 Feb. But wxDateSpan::Days(14) is equal to wxDateSpan::Weeks(2) Finally, notice that for adding hours, minutes and so on you don't need this class at all: wxTimeSpan will do the job because there are no subtleties associated with those (we don't support leap seconds). .SH "PARENTS" .SH "INCLUDE FILES" wx/datetime.h .SH MEMBERS .SS wxDateSpan (int years = 0int months = 0int weeks = 0int days = 0) Constructs the date span object for the given number of years, months, weeks and days. Note that the weeks and days add together if both are given. .SS wxDateSpan Add (const wxDateSpan& other) .SS wxDateSpan& Add (const wxDateSpan& other) .SS wxDateSpan& operator+= (const wxDateSpan& other) Returns the sum of two date spans. The first version returns a new object, the second and third ones modify this object in place. .SS static wxDateSpan Day () Returns a date span object corresponding to one day. .SS static wxDateSpan Days (int days) Returns a date span object corresponding to the given number of days. .SS int GetDays () Returns the number of days (only, that it not counting the weeks component!) in this date span. .SS int GetMonths () Returns the number of the months (not counting the years) in this date span. .SS int GetTotalDays () .SS int GetWeeks () Returns the number of weeks in this date span. .SS int GetYears () Returns the number of years in this date span. .SS static wxDateSpan Month () Returns a date span object corresponding to one month. .SS static wxDateSpan Months (int mon) Returns a date span object corresponding to the given number of months. .SS wxDateSpan Multiply (int factor) .SS wxDateSpan& Multiply (int factor) .SS wxDateSpan& operator*= (int factor) Returns the product of the date span by the specified factor . The product is computed by multiplying each of the components by the factor. The first version returns a new object, the second and third ones modify this object in place. .SS wxDateSpan Negate () Returns the date span with the opposite sign. .SS wxDateSpan& Neg () .SS wxDateSpan& operator- () Changes the sign of this date span. .SS wxDateSpan& SetDays (int n) Sets the number of days (without modifying any other components) in this date span. .SS wxDateSpan& SetYears (int n) Sets the number of years (without modifying any other components) in this date span. .SS wxDateSpan& SetMonths (int n) Sets the number of months (without modifying any other components) in this date span. .SS wxDateSpan& SetWeeks (int n) Sets the number of weeks (without modifying any other components) in this date span. .SS wxDateSpan Subtract (const wxDateSpan& other) .SS wxDateSpan& Subtract (const wxDateSpan& other) .SS wxDateSpan& operator+= (const wxDateSpan& other) Returns the difference of two date spans. The first version returns a new object, the second and third ones modify this object in place. .SS static wxDateSpan Week () Returns a date span object corresponding to one week. .SS static wxDateSpan Weeks (int weeks) Returns a date span object corresponding to the given number of weeks. .SS static wxDateSpan Year () Returns a date span object corresponding to one year. .SS static wxDateSpan Years (int years) Returns a date span object corresponding to the given number of years. .SS bool operator== (wxDateSpan& other) Returns true if this date span is equal to the other one. Two date spans are considered equal if and only if they have the same number of years and months and the same total number of days (counting both days and weeks). .SS bool operator!= (wxDateSpan& other) Returns true if this date span is different from the other one. .SH "SEE ALSO" Date classes overview , wxDateTime .SH "AUTHORS" Documentation content by Julian Smart, Robert Roebling, Vadim Zeitlin, Robin Dunn, et al Conversion to manpage format by Arnout Engelen (http://bzzt.net), bugreports welcome.