360-day year in prophecy

Is there any significance to the number of days for the year of the flood being 360 days, when you add up all the days given in Genesis? I think the great tribulation period or the 2nd half of the "Week" is simply based on a 360 day year (from the middle of the Week to the end of the Week is 1260 days). Whether the rest of the 70 Weeks are 360-day years, or 365+-day years, only matters if you're trying to come up with what decree began the 70 weeks prophecy.

If the 2300 mornings and evenings of Daniel 8 don't apply to Antiochus IV (1150 mornings and 1150 evenings combined from his desecration of the temple to its restoration) but the 70th Week, then it must be from the middle of the Week (the Antichrist's AOD) to the anointing of the Millennial Temple.