VBA Look down column to find specific criteria then SUM cell after criteria met cell - excel

Question

Currently, I'm trying to figure a way to look down a single column to find a specific criterion and in this case, I want to find dates that are less than 4/16/20. Once that criteria is met, I want to SUM the cell below for all met criteria in that column. This is an image of my dataset
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After doing some googling the closest I found was the code below which leads me to the idea that change information after offset to compute what I want.
Using "If cell contains" in VBA excel
Sub AddDashes()
Dim SrchRng As Range, cel As Range
Set SrchRng = Range("RANGE TO SEARCH")
For Each cel In SrchRng
If InStr(1, cel.Value, "TOTAL") > 0 Then
cel.Offset(1, 0).Value = "-"
End If
Next cel
End Sub
Not sure if I'm on the right track. It would also be nice If I would be able to amend code to check a range vs 1 column, thanks.

Answer 1

In this example you need to select the range of dates (1 row at a time only) to run the code. This also allows you to input the date (I'm assuming it changes over time so this should be helpful)
Sub SumByDate()
Dim DateRange As Range
Dim c As Range
Dim d As Range
Dim SearchDateInput As String
Dim SearchDate As Date
Set DateRange = Application.InputBox("Select a range", "Get Range", Type:=8) 'Select Date Range
SearchDateInput = Application.InputBox("Enter A Date") 'enter as mm/dd/yyyy
SearchDate = DateValue(SearchDateInput) 'this converts date entered as string to date format
For Each c In SrchRng 'for each date in list of dates
Set d = c.Offset(1, 0) 'pionts out cells to sum- in this case the cell beneath the date
If c < SearchDate Then 'if date is less than input date
Sum = Sum + d 'sum the date if true
End If
Next c 'goes to next date in row
DateRange.Cells(1, 1).Offset(2, -1) = Sum 'inputs all summed values into cell that is two down, one to the left of first date cell
End Sub

Answer 2

Sub SumByDate()
Dim SrchRng As Range
Dim c As Range
Dim d As Range
Dim lCol As Long
Dim ColLtr As String
Dim SearchDate As Date
lCol = Cells(2, Columns.Count).End(xlToLeft).Column
ColLtr = Split(Cells(1, lCol).Address, "$")(1)
Set SrchRng = Range("B2:" & ColLtr & "2")
SearchDate = DateValue("04/16/2020")
For Each c In SrchRng
Set d = c.Offset(1, 0)
If c < SearchDate Then
Sum = Sum + d
End If
Next c
Range("A4") = Sum
End Sub