"Is it future or is it past?"
I recall media outlets before the premiere quoting Lynch (or was it Frost?) saying how people should keep their eyes peeled for clues/information, and once the season was over, people would be going back through it to see how it all pieced together.
Here's what I've got so far, reposted for anyone who missed it underneath all the spoiler tags. Dates are theoretical... but order should be there or thereabouts.
Mid February 2014... Coop arrives back in time in NYC after being thrown into the nonexistence by the Doppelganger Arm. Sam and Tracy get killed. Cooper falls down into the purple place and is stopped going into the outlet marked 15 and is lead up onto the space box by the woman without eyes who throws a lever...
02-20-14 Thursday. Night of the school meeting. Ruth Davenport gets murdered.
02-21-14 Ish. Mr C hires Ray and Darya.
02-22-14 Saturday. Bill gets arrested. Phylis gets murdered by Mr C.
02-27-14 Dougie goes AWOL at work and at home. Diner scene with Mr C, Ray, Darya and Jack
02-28-14 Mr C kills Jack. Kills Darya that night. Downloads information on the Prison where Ray is being held. Hawk goes walking in the woods and talks to Margaret on the phone.
03-01-14 Coop meets Laura in the lodge, Leland, the good arm, and then as he is about to swap places with Mr C (at 2:53PM) is thrown back in time by the doppelganger Arm. Dougie is having sex with Jade. Mr C is hauling ass. Coop arrives back from the space box, and is sent into the outlet marked 3. Swaps with Dougie. Mr C vomits everywhere and is subsequently taken to prison for reasons currently unknown. Dougie/Coop evades assassination and goes and plays slot machines at the Silver Mustang. Agent Tammy Preston gets back from NYC and reports on her findings there. Albert and Gordon find out that Mr C has been taken to the prison in South Dakota (same one where Ray was taken).
Dougie/Coop gets taken home to Lancelot court, and meets Janey-E.
03-02-14 Dougie/Coop has pancakes and coffee for breakfast with Janey-E and Sonny Jim. Cole meets with Denise. Cole, Gordon and Tammy fly to South Dakota and meet with Mr C. Cole and Gordon discuss the meeting twilight that night.
The sheriff's office stuff is almost impossible to place at this point. Lucy is wearing the same outfit in every scene so far which further confuses things.
If you slot in the 'night' scenes in Twin Peaks (including Road House performances), it throws everything else off... which makes me think the stuff we're seeing in Twin Peaks isn't happening perfectly in order with everything else where we're given dialogue that grounds us around *when* the switch is supposed to take place. 'Day after next', 'Tomorrow', obviously Mr Jackpots plays slots, goes home that night and gets up the next day.
At some point the Twin Peaks scenes are going to slot in with everything else though.
The March 1st date comes from a tenuous place though. American Girl is wearing a watch that says SAT 01 above the time, when it ticks over to 2:53 PM and Coop and Dougie switch.
25 years after Laura Palmer's murder in February 1989 is 2014. 2014 only has two Saturday 1sts (March and October). March is closer to 25 years later and works better if we presume Wally (stated as 24 years old on screen) was conceived in January or early February, making a birthday prior to October 1st much more unlikely.
Of course, then you have the problem of Andy saying Wally was born on Brando's birthday, but that's *impossible* because Brando's birthday is in April, and Lucy finds out she is pregnant in late Feb / early March.
So, yeah. That's what I've got so far from paying attention to references to days of the week, or references to the day Mr C is supposed to go back in.
And obviously it isn't nighttime in NYC at 3:53 EST. We see daytime South Dakota through the curtains, then nighttime NYC when Sam and Tracy are about to get murdered, then daytime South Dakota again. Definitely some time travel! Also the day of the switch can't be the same day Sam and Tracy get killed, because Agent Preston gets back from NYC having looked into Sam and Tracy's death on the day of the switch. It's still daytime in Philadelphia when she shares her findings from NYC, and it's all but confirmed that that is the same day as Mr C's car accident.