Formula for irregular row divisions

Greetings,
I have computer model output files that have >100,000 rows. Column A is the model time (days). Column B is a rate (meters/day). Each day is broken up into pieces, but not everyday is broken into the same number of pieces, i.e. day 1 consists of 22 rows while day 2 consists of 5 rows. What I need is the Average rate (meters/day) for each day, i.e. averaging the 22 rows for day 1 in Column B and averaging the 5 rows for day 2 in Column B, etc... I'm trying to write a formula that I can cut and paste because I have to do this for over 130 different model outputs. I attached an example of the data. Any help is much appreciated.
Thank You,
Zach

dredwolf,
Sorry if my explanation was unclear. It's hard to put into words exactly what I need help with.
In my attached example spreadsheet, Column A is the model run time and Column B is the rate at that time in the model. Example, at time equals 0.001 days, the rate is -0.00056305 m/day (Row 2 for Columns A and B, respectively) (*NOTE: the negative rate value are because it's in the downward direction).
In the spreadsheet, day 1 (time equals 0.001–0.8045) is 21 rows. Day 2 (time equals 1–1.8045) is 22 rows. Day 5 (time equals 4–4.625) is 3 rows.
My goal is to get the average Rate (m/day) for each year (Time equal to 0–364 days, 365–730 days, 731–1095 days, etc...). The full spreadsheet is 30 years (10,956 days), and I have 132 spreadsheets
Therefore, I would love to have a formula so I can copy and paste into the other 131 spreadsheets after I complete the first spreadsheet.
What I don't know is how to write a formula that makes Excel average only the values in Column B that correspond to time equal to 0–364, 365–730, 731–1095, etc...

dredwolf,
Thank you so much! Yeah made a mistake in first post, I need yearly averages, not daily, but your formula looks to work for daily. I have no idea what it means , but the values are correct! Do you what I would need to change for it to compute yearly averages?
Thanks Again!

dredwolf,
Wow, thank you! This is saving my life . If you're up to it, the 3rd year is the first leap year.

The start year is 1982. 1984 is the first leap year in the series.
Thanks

Much thanks to dredwolf for your help, I really appreciate it. If anyone knows how to edit dredwolfs above formula for annual averages to account for leap years, I would be forever in your debt .

Thank you very much!!! Leap years really mess up efficiency when using Excel. Good luck and many thanks for even trying

Glad you're enjoying the challenge It would take me 18 YEARS to complete anything like this.

dredwolf and kvsrinivasamurthy,
Thank you both very much!!!!! This is a HUGH help!!! Saving me hours of time and millions of headaches
-Zach