How to add seconds to a time field

I had a member that wanted a one line solution on how to add seconds to a time field that was in character format. This is what I came up with. I also made it into a custom function if anyone else needs this functionality.

Option Explicit

Sub Main
    Dim strTime As String
    strTime = "11:59:24"
    MsgBox addSeconds(strTime, "65")
End Sub

Function addSeconds(sTime As String, sIncrement As String) As String
    If Not IsDate(sTime) Then
        addSeconds = "Error"
    Else
        addSeconds = TimeSerial(Hour(sTime), Minute(sTime), Second(sTime) + CInt(sIncrement))     
    End If
End Function