Three and a Half Days
LyingInSpirals
Summary:
When Harry gets quickly bored of staying in Diagon's main alleyway, he devises a plan to explore the rest of the alley, to the exasperation of Tom the Barman.
He never thought he'd discover a mild version of a rare magical skill and gain a passion in rune craft while doing it, but he can't really complain as it eventually gets him a boyfriend too.