According to the Tale of Years, Boromir set out from Gondor on July 4 on his search for Imladris.
Early in July Frodo Baggins, walking back to Hobbiton from a trip to examine the house at Crickhollow he purposed to buy, paused as if listening, for he swore he heard as if from afar the sound of a distant horncall.
Samwise Gamgee, who’d slipped into his Master’s study to start a list of supplies they’d need when at last he and Frodo Baggins set off on the journey Gandalf had set them, hopefully in the company of Meriadoc Brandybuck, raised his head. Meriadoc Brandybuck, who was conferring in Budge Hall with Fatty Bolger, also seemed to hear a distant horn ringing on the morning breeze. Peregrin Took, halfway between Brandy Hall and Tuckborough, paused, turning southwards.
Aragorn son of Arathorn, on his way northward to check the defenses against Angmar one last time ere he returned to the borders of the Shire to await the coming forth of the Ringbearer, drew on Roheryn’s reins. “What is that I hear, my friend?” he asked the horse. Roheryn whickered and tossed his head, then turned northward once more.
Gimli son of Gloin, listening with half an ear to the counsel being taken between his father and Daín and the envoy from Brand of Dale, turned, uncertain of what he’d heard. In the great woods Thranduil’s golden-haired son Legolas paused in his discussion with his father and brother on how the warning to Gandalf should be worded that the creature Gollum had escaped, his attention caught by a mysterious echo.
Gandalf had stopped to rest in a hollow not far from Tharbad. Hearing the sound of a familiar horn in the far distance, his attention fixed southeastward. “The Horn of Gondor!” he murmured as he tightened his grip on his rugged staff, tapping the knowledge that lay therein. “Irmo sends warning. The Enemy now makes the first moves in his most recent game. I must hurry! We are summoned to our places so as to best oppose him!”
In moments his campsite was cleared as if he’d not paused there at all, and he was walking southward again at all speed, intent on reaching Isengard within a week.
And having sounded his horn at the gates of the White City, the Steward’s elder son lightly kicked his heels into his steed’s ribs. He would stop in Rohan where he hoped to acquire a better horse to ride northward on. He had his quest to fulfill. The horse broke into a gallop, and they headed northward toward the gate in the Rammas Echor, headed now toward Amon Dîn and then westward through Anórien.
From the keel of the spur of rock that split the city in half peered Faramir of Gondor, his attention fixed on the receding form of his brother. This quest, he knew, ought to have been his own. Then he turned reluctantly to return to the Citadel, to hear from his father and the Council how much in the way of supplies they were willing to send east into Ithilien with him. The defense of Gondor must continue.