Insert text in cells when above cell meets condition - vba

Question

I have a schedule sheet for the whole year for a group.
The third row has all the dates of the year, the next couple of rows has the name of each group member.
Members specified in A4:A9.
Holidays are specified in cells A20:A28.
So, what I want to do, probably through VBA, is to make a rule like with conditional formatting, that inserts the word "Holiday" in B4:B9 if B3 matches a date in A$20:A$28, and then into C4:C9 if C3 matches and so on.
Now I cannot write this condition in every cell since it's a schedule used by every member, which is the suggestion I often got from googling, and I can't do it with conditional formatting, so I'm guessing VBA is the way to go, but the VBA code I've found so far seems to use specific cells and wouldn't go through each column.

Answer 1

Without questioning your general approach, a simple code that does what you plan to do could work like the following:
Option Explicit
Sub markhd()
' get calendardays, holidays and employees somehow into collections
' that can be looped. Since that information is stored in a worksheet,
' using ranges is one way to achive that
' holidays
Dim rhd As Range
Set rhd = ActiveSheet.Range("A20:A28")
' group employees
Dim remp As Range
Set remp = ActiveSheet.Range("A4:A9")
' calendar days
Dim rcal As Range
Set rcal = ActiveSheet.Range("B3:NB3")
Dim c As Object
' Loop every day (every c-object in your calendar days),
' then write "Holiday", if it matches an entry in your holiday-range
For Each c In rcal
If Not IsError(Application.Match(c, rhd.Cells, False)) Then
remp.Offset(0, c.Column - remp.Column).Value = "Holiday"
End If
Next c
End Sub
Note:
The concept #EganWolf mentioned is to look for similar objects (calendar days in this example) and iterate through them, performing an action (writing "Holiday") if a check is passed (calendarday is in the range of holidays). There is a gazillion of different ways implement this, i merely posted one easy to follow example
Looping each and every calendar day we're doing 365 iterations here, attempting to match each calendarday in the 9 holidays.
However, we could do this the other way around: loop the 9 holidays, match them in the 365 calendar days, therefore looping only 9 times. Performance could theoretically swing both ways, since despite having less iterations, a single iteration could take longer... but, obviously, at 365 days performance is merely a theoretical problem.
Hope that helps!