question about date calculations

[ces005]

Hi,

I have some questions about date logic. Is it safe to do date comparison logic like cell A5's value being < 1/1/06 or do I need to use some date functions?

Also, if I want to subtract some number of weeks from a date (in mm/dd/yy format), should I just take the cell's value (e.g. B5) and subtract 21 from it (if I want to subtract 3 weeks)? I would prefer to not be dependent on excel addons (e.g. date functions), but don't know if my logic would be safe without using date functions. Thanks.

-Eileen

 

[xapie128]

Internally, Excel stores dates as the number of days since 1/1/1900 (that's the default, but can be changed to 1/1/1904 in the Tools menu). With the default, 1/1/1900 = 1; today, 9/16/2006 = 38,976. You can demonstrate this yourself by entering a date, then formatting the cell to Number format.

So, to answer your first question, it is easiest to compare one cell to another; in your example have 1/1/06 in a cell then compare A5 to the cell that contains 1/1/06.

Regarding your second question, Yes you can do that. If the cell is formatted to display dates, then 9/29/2006 - 21 would result in 9/8/2006.

 

[ces005]

question about readonly cells

Hi,

I have a cell (e.g. C4) where I have a visual basic script to populate the field. How do I make that cell uneditable? I have not made the element an activeX type of control because I am not that sophisticated.

-Eileen

 

[ces005]

Let me change my question.

Cell D3 is a picklist.

How do I set it up so that when a person selects a value from the picklist, this triggers a macro to be called to update some pther cell values (these are computed based on the selected item).

 

[ces005]

oops -- I added my questions to some unrelated question instead of creating a new post. Sorry.