1. Base person
I used Theseus,  the son of Aegeus, as a reference because I could identify the year of his  ascension to the King of Athens and associated with many people of the time.
      2. Theseus' reign  years
        The chronicler of  the first century BC, Castor of Rhodes, tells of the reigns of successive  Athenian kings and notes that in the 12th year reign of the 29th Athenian king  Aeschylus, the first Olympiad was held in which Coroebus won the footrace. [1]
        The first Olympiad  in which Eris's Coroebus won a foot race is known to have been in 776 BC, and  the year of Aeschylus's ascension is 787 BC. [2]
        Counting backward  from Aeschylus according to the length of his reign, Theseus's reign is 30  years, from 1239 BC to 1209 BC.
      3. Theseus' age at  accession
        Aegeus, king of  Athens, who was old and had no heir, summoned to Athens his son Theseus, who  had been born to Aethra, the daughter of Pittheus of Troezen. [3]
        Theseus was then  sixteen years old. [4]
        Deucalion, son of  Minos, then married off his sister Phaedra to Theseus in order to make an  alliance with Athens. [5]
        This marriage  seems to have happened when Minos was dead and Aegeus was still alive.
        Theseus also had a  son Hippolytus by Antiope, born before his marriage to Phaedra. [6]
        Based on the  above, it is estimated that Theseus was born in 1263 BC when Theseus ascended  to the throne of Athens when he was 24 years old.
      4. Hercules’s birth  year
        Theseus, then  seven years old, is said to have seen Heracles sitting on a lion's skin when Heracles  visited Pittheus, grandfather of Theseus. [7]
        It is believed  that this happened after Heracles defeated the Cithaeron’s lion at the age of  18, with an age difference of at least 11 years. [8]
        Also, when Theseus  was sixteen years old, the deeds of Heracles were widely known. [9]
        Based on the  above, I estimated that Heracles was born in 1275 BC, 12 years earlier than  Theseus.
      5. The year of the  Argonauts and the Calydonian boar hunt
        During the three  years Heracles served under Lydia's Omphale, there was the Argonauts, the  Calydonian boar hunt, and Theseus' exploits in the Isthmus of Corinth. [10]
        Theseus' exploits  on the Isthmus of Corinth, at the age of 16, are estimated at 1247 BC. [11]
        Theseus also  participates in the Argonauts from Troezen, and in the Calydonian boar hunt  from Athens. [12]
        Therefore, the  Argo expedition dates to 1248 BC, and the Calydonian boar hunt to 1246 BC.
      End