A direct descendant of Isildur, Arahad succeeded his father Aravorn to become the tenth of the Chieftains of the Northern Dúnedain. Several notable events occurred during his lifetime, but few would have affected him directly (he was, for example, six years old when the Golden Hall of Meduseld was completed in Rohan). Perhaps the most directly relevant of these events would have been the introduction of pipe-weed into the Shire from Bree in the early years of his rule. These were regions where the Dúnedain had a presence, but we don't know whether pipe-smoking was taken up by them at this early date (though we do know that Arahad's descendant Aragorn smoked a pipe from time to time).
Arahad II seems to have enjoyed a relatively peaceful rule, but that peace was not to last. He was succeeded by his son Arassuil after sixty-five years as Chieftain, and soon afterwards the Orcs began to make incursions into the lands of Eriador.
The date of Arahad's birth appears only in The History of Middle-earth volume XII, The Peoples of Middle-earth. It cannot therefore be considered completely reliable.
In the name Calenhad, the -had ending simply means 'place' or 'location'. Conceivably the same meaning applies to the name Arahad, but 'royal place' seems a strange name for a Chieftain.