Welcome to the forum!

All day events have an issue setting the reminder that long. You may have an issue with your start time.

A workaround like this might meet your needs. I used start date as 4 days from current date. 
Sub SetReminder()  Dim ol As Outlook.Application
  Dim olAp As Outlook.AppointmentItem
  Dim d As Double
  
  Set ol = New Outlook.Application
  Set olAp = ol.CreateItem(olAppointmentItem)
   
  With olAp
    .Subject = Cells(7, 2) & " - " & Cells(7, 4) & " - " & Cells(7, 5)
    .Location = Cells(7, 3)
    d = Now + 4 * 24
    d = DateSerial(Year(d), Month(d), Day(d))
    .Start = d 'Cells(7, 16)
    .End = d + TimeSerial(23, 59, 0)
    .AllDayEvent = False
    '.AllDayEvent = True
    .ReminderMinutesBeforeStart = 3 * 24 * 60
    .ReminderSet = True
    .body = Cells(7, 19)
   .display
  End With
End Sub