Find a date and clear contents underneath target cell - excel

Question

I have a Macro that loops through one column that hold dates that are not random (they go vertically from old to more recent ),then finds every date that is greater than Now () then goes to its adjacent cells and clears them
it works fine , except that the looping takes a small bit of time, which i believe could me much faster if the Macro wouldn't loop against all values in the column(500 rows) but instead just stops at the first cell match , then goes to its adjacent cells and clear all contents from that row till the bottom of the table ( ie if the match is at row 15 , then it clear contents from row 15 all the way down to 500 ) without having to check every single row
The code below as described is designed to loop through every value , i need it to stop at the first match and clear contents of adjacent cells underneath in the range the macro covers
can somone please help me acheive this
Dim R As Long
For R = 1 To 500
If Cells(R, "A").Value >= Now Then Cells(R, "B").Value = ""
If Cells(R, "A").Value >= Now Then Cells(R, "C").Value = ""
Next
End Sub

Answer 1

Using your methodology, if you want to know how to drop out of a loop once the criteria are matched - you would use an Exit For. You also can clear column B and C at the same time, like so:
Dim R As Long
With ActiveWorkbook.Sheets("Sheet1")
For R = 1 To 500
If .Cells(R, "A").Value >= Now Then
.Range("B" & R & ":C500").ClearContents
Exit For
End If
Next
End With
In the above, I've also added reference to the sheet. This is always good practice to prevent possible errors once more than one sheet is available.

Answer 2

Here's an example with a binary search.
Option Explicit
Public Sub ClearByDates(Optional targetDate As Variant = Null)
Dim thisSheet As Worksheet
Dim activeRange As Range
Dim lowerRow As Long, higherRow As Long, thisRow As Long
Dim thisDate As Date
' If no date is provided, assume today is the cutoff
If IsNull(targetDate) Then targetDate = Date
' Assuming that we're putting this code in the worksheet that you want to _
clear. If you decide to put it in a separate module you can either: _
(1) Pass in the worksheet you want to modify as an argument, or _
(2) Explicitly set the worksheet you want to modify using ActiveWorkbook.Worksheets(Name)
Set thisSheet = Me
Set activeRange = thisSheet.UsedRange
With activeRange
' Not only is it cleaner if you use With, you get better performance in VBA _
because it's a hint that the object should be kept loaded and ready.
' Getting the range of rows with values
lowerRow = .Rows(1).Row
higherRow = lowerRow + activeRange.Rows.Count - 1
' Don't start processing until you're in the date range; _
this should handle most common worksheet header situations.
Do Until IsDate(activeRange.Cells(lowerRow, 1))
lowerRow = lowerRow + 1
If lowerRow > higherRow Then Exit Sub
Loop
' Use a binary search to find the first row where the date is _
greater than or equal to the target date.
Do Until lowerRow >= higherRow - 1
thisRow = (higherRow + lowerRow) / 2
thisDate = .Cells(thisRow, 1)
Debug.Print "Row " & Right(" " & thisRow, 7) & ": " & Format(thisDate, "YYYY-MM-DD") & " ";
If thisDate >= targetDate Then
Debug.Print ">= " & Format(targetDate, "YYYY-MM-DD");
higherRow = thisRow
Else
Debug.Print "< " & Format(targetDate, "YYYY-MM-DD");
lowerRow = thisRow
End If
Debug.Print " (lowerRow = " & lowerRow & ", higherRow = " & higherRow & ")"
Loop
' Assuming we just want to clear columns B & C. This can easily be adjusted _
to clear all columns to the right by using .Columns(.Columns.Count) in the _
ending range.
thisSheet.Range("B" & thisRow & ":C" & .Rows(.Rows.Count).Row).ClearContents
End With
End Sub