1 Corinthians 16:8

But. will tarry at Ephesus until Pentecost;

'Pentecost' -'The mention of Pentecost does not imply that the early church kept that day as. religious holiday. Instead, it marks it as. time period in the same way as does this sentence: "I will wait until Labor Day."' (Willis p. 606)

'As the second of the three great pilgrimage feasts in Israel it concluded. cycle of time begun at Passover..It was named Pentecost because it fell on the fiftieth day after the offering of the barley sheaf during the Passover celebration.' (Zond. Ency. p. 692)

Looking at. modern calender, the general time of year that this festival was held would be late May.