Path of Exile has been running for many seasons, and many players are deeply interested in the story behind Wraeclast. Here is an official questions and answers about the poe lore:

 

Does the PoE calendar (Lurici, Vitali, Verusi etc) match the real-world calendar?

The calendar used by the Eternal Empire does not completely match what players know from their own lives. It has seven days of the week, but there are thirteen longer time spans known as moons.

The days of the week were generally named after the primary components of existence as the Eternals believed them to be: Solaro, Lunaro, Fiero, Glacio, Galvano, Kaso, Sacrato.

The thirteen moons of the year were generally created in honour of certain renowned figures, or naturally arose as part of the harvest cycle: Verusi, Divini, Derivi, Phreci, Caspiri, Astrali, Eterni, Atziri, Vivici, Lurici, Sagari, Vitali, Azmeri.

Both of these categories were subject to significant drift in meaning and spelling over the centuries.

Does the PoE world have seasons (spring/summer...)?

Wraeclast does indeed experience seasons. Derivi emerged from a celebration of the harvests of the cooler season when the leaves turned vibrant colours and fell. Astrali was marked by the arrival of snow and the Aurora Astralis. Vivici brings a celebration of life returning to the land for the year, and Vitali was a time of heat and sun.

How did Veruso get the Ankh of Eternity? Did he find it or did someone give it to him?

Much has been lost to history, but the Ankh of Eternity required what was described as ‘an Azmeri ritual' to activate. It is a safe guess that the Azmeri already had it in their possession when Tarcus Veruso led them down into their new land. Inscriptions upon it described it as a gift from the Vaal to Veruso, but the Vaal had long been absorbed into the Azmeri culture and lineages at the time of his leadership. More likely, it was a gift from the 3,126 Vaal survivors of the Fall, given to the Veruso line, perhaps to one of Tarcus' ancestors, as thanks for taking in the last remnants of their civilisation.

Where did all the Virtue Gems come from? Was the Beast the reason behind their creation? How many virtue gems are there?

The Virtue Gems are all sourced from mines on Mount Veruso, under Highgate. It is impossible to be completely certain with the limited tomes I have available on the subject, but the Beast's presence under that mountain and the fact that Virtue Gems cannot be found anywhere else in the world does indeed suggest a connection. The number of Virtue Gems in existence cannot be ascertained, any more than one might count the grains of sand on a beach.

Alano Phrecia 'Drove away the pervasive darkness', was that the Vaal Oversoul?

The pervasive darkness that Alano Phrecia drove away is likely the same darkness that the exile releases in the Vaal Ruins near the Forest Encampment. The Vaal Oversoul was merely a construct built to house that darkness, like a massive totem.

Why was Eramir exiled?

A memory found in the Archives may shed some light on this:

“I used to pride myself on taking care of these tomes, but the ancient treatises concerning the Vaal... should be burned. He's making me research for him, and the things I am reading about concern the destruction of all mankind.”

“I would think my fears of the end of the world are ridiculous... except... it's happened before. I must run... I must flee... and take my secrets with me.”

Zana had this to say about that memory: “I've never met him directly, but I think I know whose memory this was. It's someone Helena talks about: Eramir. I believe he lives with the Azmeri now.” It should be noted that Zana knew Eramir when she was very young, having called him ‘Uncle Eramir' on at least one occasion, so she is likely correct that this was his memory. However, Zana never met him as an adult, so there's no way to be sure.

If it was indeed Eramir's memory, the 'he' that was making him research would definitely have been Dominus.

When asking an Exile to bring the golden hand, Yeena says 'When the spirit of the altar awakes, I will share it with you.' Whose spirit was it? Whose altar is it? Why does she want it to be awoken?

Yeena believes she is guided by what she calls the Spirit. She believes it is in all things. Here she is referencing generally the ‘spirit' of the stones of the altar, the energy inside it, not a specific entity. She wants to awaken this altar because she believes the Spirit asked her to do so.

The Good Man was Saint Corutino the Golden Hand, who lived in Phrecia Cathedral, now called Fellshrine. Later, Archbishop Geofri was slain at the foot of Corutino's shrine with Maligaro's Etcher. Archbishop Geofri later reanimated as an undead guardian.

Did the ancient Azmeri descend from the mountains alongside Tarcus Veruso?

The bulk of them did, and they founded the Eternal Empire. The Azmeri of the Forest Encampment did not do so, and are descendants of their original culture.

How exactly does the Vaal Oversoul set free? Why do we need the Apex if activating the seal seems to set it free?

The darkness that ends up inhabiting the Vaal Oversoul was likely the same one imprisoned by the forces of Alano Phrecia. The exile breaks that seal in the Vaal Ruins near the Forest Encampment. Later, the Apex is used in a Vaal temple to summon the darkness into the Vaal Oversoul's mechanical body so that it can be destroyed.