So, I've been narrowing down my personal timeline and thought I would share some personal insights I had regarding Age of Ultron, Civil War, Black Widow, and Black Panther. For the most part, it matches the site, it's just a little more specific and falls later in April causing a crossover into May. (These are just for the main events of each movie)
Age of Ultron- April 15th-23rd 2015.
Civil War- April 24th, 2016, April 27th-May 1st 2016, May 15th, 2016.
Black Widow- April 30th-May 3rd 2016, May 15th, 2016.
Black Panther- May 4th-12th 2016.
I came up with these dates wanting to follow these points of evidence (some of these have been mentioned before, I'm just including all of my reasoning):
- In Civil War, Zemo mentions that he's been working on his plan for "over a year". So, Civil War should at least be over a year since Age of Ultron. Sokovia would fall on April 22nd, 2015, and Zemo's line would fall on April 29th, 2016.
- AoS shows us Peggy Carter's obituary. In it, her age is listed as 95 and she was born on April 9th, 1921. So, her death has to occur after April 9th, 2016. Here her death would fall on April 24th, 2016.
- As most here know, the beginning of Civil War shows a March dated paper in Lagos and the main events of the movie pick up the following month. The scene at the Avengers compound would be on April 24th.
- Civil War also tells us that Charlie Spencer wanted to spend his Summer in Sokovia, so the closer we can get Age of Ultron to Summer while still being April, the better.
- Ant-Man ends in October and mentions what seems to be references to Spider-Man. If Peter received his powers 6 months prior to Civil War, then him saying this on April 28th fits.
- Clint and Scott are both placed under house arrest for 2 years due to the events of Civil War. Scott's sentence ends in early May 2018 and Clint is shown to still be under it in Mid-May 2018. Once again fitting with April 2016 with them receiving their sentences in May 2016.
- Black Panther should begin a week after T'Chaka's death (April 27th, May 4th).
- I came up with days of the week from the movies themselves. For example, Age of Ultron should begin on a Wednesday as it's a few days before the party we're told is going to be on Saturday (April 18th). Counting the days after the party has the Sokovia battle fall on the 22nd and I have the scene of Clint returning to his farm on the 23rd. With Civil War, the airport battle should fall on a Friday (April 29th) as Peter then spends the rest of the weekend in Germany before Tony returns him home on Sunday. The Accords signing is a couple of days earlier on Wednesday (April 27th) and a few days prior is Ross at the compound (April 24th).
The reasoning behind Civil War having more of an early April placement in the past is due to the package Tony receives being dated April 14th. Black Widow shows us this scene happens 2 weeks after the events of that movie (her helping Steve in the Raft escape), and there's no way to squeeze the events of CW, BW, and BP before April 14th and still fit with Lagos being "last month" in March. Especially with Peggy's death needing to occur after April 9th. So, like certain dates, I feel like this should be ignored, which the site here has already decided to do.
These dates also account for AoS and for the most part fit well with where the site has the show. For example, 2x14 of AoS mentions a "Taco Tuesday" if you date the surrounding episodes, you get 2x11 ending on March 28th and 2x12 as beginning on April 3rd. The site currently has 2x11 as the last episode in March and 2x12 as the first in April, so it fits perfectly with Age of Ultron. Also, using the "Taco Tuesday" date allows 2x19 and Coulson having the Avengers go after the Scepter occur on a Wednesday, matching perfectly with the movie also needing to begin on that day of the week.