Yeah, he's got a Snake Plissken meets Gibson Mad Max vibe going on.
And I am into that.
Also got to chuckle at the inverted colours he's wearing. It's a little thing but I like it.
First photos of Alden as Han Solo: http://www.tmz.com/2017/05/19/star-wars-young-han-solo-set-photos/
Eh, I'll have to see him in motion.
See, to me it looks like he's about to tell Lee Van Cleef to call him 'Snake'.
Yes, BBY/ABY - Before Yavin/After Yavin - is the standard unit of day/month/year measurement in the Star Wars universe. With that in mind:
TPM - 32 ABY
ATOC - 22 ABY
ROTS - 19 BBY
ROGUE ONE - 13 BBY - 0 BBY
HAN SOLO MOOBIE - 10 BBY
ANH - 0 BBY/0 ABY
ESB - 3 ABY
ROTJ - 4 ABY (or 6 months after ESB)
TFA - 34 ABY
It's technically "Before the Battle of Yavin/After the Battle of Yavin."
And yes, when you get down to the granular, you're talking about a matter of months here and there. Like Rogue One probably takes place anywhere from a month to a few weeks before the start of ANH, which in turn probably plays out over the course of a few weeks to a month.
But I was using Wookiepedia, which is the Definitive Source for these kind of dates.