how can i know if there are a sundy between 2 dates?

[fleurlisalu]

how can i know if there are a sundy between 2 dates? i have a condition for calculating a indicator, for exemple: date1=01/07/07 et date2=19/07/07, how can i know there are a sundy between date1 and date2? i have a table of "day" to know "what day is today?" how can i do it? my english is terrible, i am sorry

[kcbland]

Welcome aboard! You need to calculate if the difference in dates is greater than 6, or if less than 6 the day of the week of the starting date plus the difference will include a Sunday. Any date separation greater than 6 must mean that one of the dates is a Sunday or that the number of days is greater than a week and therefore includes Sundays.

The simple algorithm is:

StartDate.DayOfWeek + (EndDate - StartDate) > 6

If 2007-01-01 is a Monday, and Monday is day of week #1 then:

1 + (2007-01-07 - 2007-01-01) = 7 (must have included a Sunday)

1 + (2007-01-04 - 2007-01-01) = 4 (could not have included a Sunday)

4 + (2007-01-04 - 2007-01-04) = 4 (could not have included a Sunday)

4 + (2007-01-07 - 2007-01-04) = 7 (must have included a Sunday)

4 + (2007-01-07 - 2007-01-04) = 7 (must have included a Sunday)

6 + (2007-01-07 - 2007-01-06) = 7 (must have included a Sunday)

1 + (2007-01-23 - 2007-01-01) = 23 (must have included a Sunday)

[fleurlisalu]

thank you so much, i will test it,