time of supply

Satendra kumar (Fight to the l (20 Points)

30 March 2019  
M/s Ramchandra associates has received some taxable services from MD Ltd. on 12.01.2020 by making a cash payment of Rs. 5,00,000 on same day . The payment was entered in books of Ramchandra associates on 16.01.2020 and in the books of account of MD Ltd. on 20.01.2020 .The invoice was issued by MD Ltd. on 18.01.2020 . what is the time of supply?