Answer: 18 days.
The second date (Date2) occurs 140 days after the first date (Date1).
If we temporarily ignore the 50 day gap, we therefore have 90 days to split in the ratio 4:1, which is 72:18.
So we have Date1 -> 72 days -> 50 days -> 18 days -> Date2.
18 days before Date2 is 30th July. QED.