Public Sub exceltojson()
Dim rng As Range, items As New Collection, myitem As New Dictionary, i As Integer, cell As Variant
set rng = Range("A2:A3")
'Set rng = Range(Sheets(2).Range("A2"), Sheets(2).Range("A2").End(xlDown)) use this for dynamic range
i = 0
For Each cell In rng
Debug.Print (cell.Value)
myitem("name") = cell.Value
myitem("email") = cell.Offset(0, 1).Value
myitem("phone") = cell.Offset(0, 2).Value
items.Add myitem
Set myitem = Nothing
i = i + 1
Next
Sheets(1).Range("A4").Value = ConvertToJson(items, Whitespace:=2)
End Sub

Sub customJSON_3()
Dim mainContainer As New Collection, tempContainer As New Dictionary, children As New Collection
tempContainer.Add "name", Range("B3").Value
tempContainer.Add "dateStart", Range("C3").Value
children.Add tempContainer
Set tempContainer = Nothing
tempContainer.Add "name", Range("B2").Value
tempContainer.Add "dateStart", Range("C2").Value
tempContainer.Add "children", children
mainContainer.Add tempContainer
Sheets(1).Range("H10").Value = ConvertToJson(mainContainer, Whitespace = 2)
End Sub

[
{
"name": "Work",
"dateStart": "2017-05-04",
"children": [
{
"name": "Next",
"dateStart": "2017-05-04"
}
]
}
]