If you're impatient, you can get it from Steam Workshop (more screenshots over there as well) or as direct download. Enjoy the game.
If you're interested in some behind the scenes information, keep reading.
What Modern Times mod is aboutThe mod intends to extend CK2 timeline. It originally just covered 1900-2015 period, currently extended to 1818-2015, but there's no special reason to stop there. I would like it to eventually extend back further.
I'm not sure how far back it will go. Probably not all the way to end of CK2 timeline, but there's no good reason to stop in 1818. It could easily go all the way back to Peace of Westphalia someday.
The mod has no plans to ever be AGOT style total conversion. Right now it touches very little other than province history. It will eventually add some period-appropriate mechanics for flavour, but it will be the same game.
The mod definitely doesn't intend to be "realistic". It is inherently silly.
CountriesThe mod currently uses vanilla map, and tries its best to model independent countries on it. There's a lot of cases which are difficult to model. Most tiny countries like Kosovo, Lichtenstein, or small HRE minors are not included, but a few with particular historical significance like Free City of Danzig and Vatican are extended to cover whole county around them. Many real world borders cross province boundaries, so in game borders will look a bit weird.
It's often not clear who counts as independent country. Vassals and protectorates are mostly simply included in liege country. The mod currently doesn't use tributaries.
Border changes generally taken at peace treaties, or at least long term truces, so mid-war changes generally not taken into account.
Vassals are almost all automatically generated - with every de jure duchy getting one vassal (duke if liege controls majority of duchy, multicount otherwise).
A few notable exceptions like Soviet member Republics, Egypt under Ottomans, Jordan under United Kingdom, and devolved Scotland follow historical patterns, but for now this is exception rather than rule. British India is divided into vassal kingdoms ruled by locals as a somewhat messy workaround for vassal limit.
Some countries have been renamed to better fit history - like "Wendish Empire" to "Commonwealth", or "kingdom of Bavaria" to "kingdom of Austria". For now no new countries have been added. Many historical "kings" and "dukes" went down a tier to better match their actual size. De jure map was adjusted somewhat, but it mostly follows CK2.
International organizations are not modelled in any way. For that matter if mod extends to times before HRE dissolution, HRE probably won't be modelled as a country, as it was a largely titular thing for very long time by then.
CharactersMod currently includes 428 historical characters as well as 26565 automatically generated characters - rulers for countries without history, vassals, and some randomly generated children for everybody. Most important countries (including all empire-tier countries) all have historical rulers.
Rulers are generally monarchs, so you won't find people like Bismark and Mussolini. Presidents are generally preferred over prime ministers, but for a few countries prime ministers are used as a lot more prominent. As CK2 doesn't support gaps between rulers, aggressive backdating is applied, so for example Konrad Adenauer starts ruling Germany as soon as WW2 ends.
Automatically generated children are very important, as that's the only way dynastic politics can happen right away, instead of only starting with second generation - as is sadly the case in vanilla CK2, where almost nobody has any daughters.
For historical characters parent-child information should generally be present, but more distant relationships aren't, as they would require adding non-ruler characters, something we don't currently do. Game engine doesn't have any way to mark one king as brother, nephew, or grandson of another without reconstructing their family tree.
This also means that currently marriage alliances between different countries are not modelled. This might change.
Cultures and religions
This results in somewhat excessive amount of religious infighting. It would probably be better to give Protestants their own branch of Christianity, but I'm not sure what would be good mechanics for that.
A few extra cultures might be helpful, but no plans to go into EU4 style twenty kinds of Germans.
I've been trying to strike a balance between countries being overly stable and falling apart too easily. The mod is definitely not there yet, but then again, neither is vanilla.
Game MechanicsRight now the only major mechanic is inclusion of Suez Canal minimod.
Pretty much all the complex code is in script generating history files.
Minor mechanical changes mod does is disabling dynastic names for all countries (so it's "Iran" not "Khameini"), and startup script to setting up sensible laws (no more gavelkind).