Option Explicit
Sub Test()
Dim rngNames As Excel.Range
Dim rngValues As Excel.Range
Dim vntValue As Variant
Dim vntIndex As Variant
Dim dtm As Date
Set rngNames = Range("B4:Z4")
Set rngValues = Range("B20:Z20")
dtm = CDate("2021-01-05")
vntIndex = Application.Match(CDbl(dtm), rngNames, 0)
If Not IsError(vntIndex) Then
vntValue = Application.Index(rngValues, 1, vntIndex)
Call MsgBox(vntValue)
End If
End Sub