qtdatetime::operator(-) Interface Reference

Public Member Functions
integer(qtdt_k_int4) function	qtdt_f_datedifference (tDate2, tDate1)
	qtDT_F_DateDifference Returns the difference of two dates in days More...
type(qtdt_t_date) function	qtdt_f_datesubdays (tDateS, nDays)
	qtDT_F_DateSubDays Returns a date that is the result of substracting days from a given date More...
type(qtdt_t_time) function	qtdt_f_timedifference (tTime2, tTime1)
	qtDT_F_TimeDifference Returns the difference of two time values More...

Member Function/Subroutine Documentation

integer(qtdt_k_int4) function qtdt_f_datedifference	(	type (qtdt_t_date), intent(in)	tDate2,
		type (qtdt_t_date), intent(in)	tDate1
	)

qtDT_F_DateDifference

Returns the difference of two dates in days

Usage:

 nDays = tDate2 - tDate1
 nDays = qtDT_F_DateDifference( tDate2, tDate1 )

Parameters

tDate2	: date to subtract tDate1 from
tDate1	: date to be substracted

Substracts one date from another and returns the difference as the number of days. If the date given in the first argument is older than the second one, then a negative value is returned.
If an invalid date is specified, the function returns the value of -HUGE(nDays) .
The function is used to overload the operator - .

type (qtdt_t_date) function qtdt_f_datesubdays	(	type (qtdt_t_date), intent(in)	tDateS,
		integer(qtdt_k_int4), intent(in)	nDays
	)

qtDT_F_DateSubDays

Returns a date that is the result of substracting days from a given date

Usage:

 tDateE = tDateS - nDays
 tDateE = qtDT_F_DateSubDays( tDateS, nDays )

Parameters

tDateS	: date
nDays	: number of days substracted from tDateS

Returns the date that is the result of a given date to which is added a number of days. If the number of days given is negative than these days are substracted from the given date.
If an invalid date is specified, the function returns the value of qtDT_T_Date(-1,-1,-1) .
The function is used to overload the operators + and - .

type (qtdt_t_time) function qtdt_f_timedifference	(	type (qtdt_t_time), intent(in)	tTime2,
		type (qtdt_t_time), intent(in)	tTime1
	)

qtDT_F_TimeDifference

Returns the difference of two time values

Usage:

 tTimeDiff = tTime2 - tTime1
 tTimeDiff = qtDT_F_TimeDifference( tTime2, tTime1 )

Parameters

tTime2	: time to subtract tTime1 from
tTime1	: time to be substracted

Substracts one time from another and returns the absolute value of the difference. Thus, even if the time given in the first argument is less than the second one, positive values are returned in all components of the type.
The function is used to overload the operator - .