Just saw an interesting video on YouTube where this man says there were 15 worldwide calendars in use during King Hezekiah's reign and ALL of them used 360 day calendars per year. Then something happened in 705 BC and within 5 years, almost all had adjusted to the current 365+ day calendar that we use now. Could explain why during Noahs time, 150 days = 5 months. Here's the link:

https://youtu.be/qRGVphxcjfY