calculate number of days

[#1]

Hello,

I have this table

ID	Grade	date
315	5	01/06/2007
	6	01/05/2009
	8	01/03/2010
	9	01/03/2011

I need to add a new column that calculates the number of days when the grade changes.example : (date of grade 6) - (date of grade 5)

any idea??

[swuehl · Accepted solution]

Try as expression

=date-above(date)

assuming that date is of date type with a numerical representation.

Regards,

Stefan

[#3]

i used the Below

anyway thanks