There was a group that posted a write up of their second session after their funnel adventure, and they had let about 6 months go by. Originally I think OD&D had a 1 week training per level requirement. So, to go from 0 to 1, I think between a week and a month or so is probably appropriate. For some occupations/class selections, it's not a stretch, i.e. from wizard's apprentice to wizard, it makes sense. From peasant to wizard, I think you need to have a bit of downtime for them to work out some on the job training... through study, meditation, etc. Or, from farmer to warrior, you need some time to hone your moves. That's probably how I'm going to run it. That'll also provide some downtime for people to do stuff like summon familiars, sell loot and buy new gear, pick up new rumors, etc.
I think making years go by is probably overkill. It also might stretch belief. Yeah, okay, it might make sense that a wizard would spend a year or two studying, but would the warrior just be sitting around on his duff during that whole time? Probably not.
Hamun Ry (Wiz 4)
Str 10 Agi 15 (+1) Sta 11 Per 11 Int 17 (+2) Luc 10 (Unholy House). Align: C. AC: 14. HP: 13. Melee +1, Ranged +2. Crit: d8, I. Save: Ref +5, Fort +3, Will +4.
Spells: 1: Choking Cloud, Comprehend Languages, Detect Magic (odd crystal growths), Magic Missile (mirror images), Runic Alphabet (Mortal) (ravenously hungry), Ventriloquism (rain of frogs)
2: Detect Invisible, Levitate (extremely difficult, d14), Mirror Image (20% chance to raise/lower luck by 1d3 points).
Equip: Ring of the Sand Djinn: +2 AC/saves, Invisibility for 1min/spellburn point, or unmake for great, unknown effect. Padded Armor, Longsword, Longbow, quiver w/20 steel-tipped arrows, 10 silver-tipped arrows, backpack, spellbook, quill and ink, sturdy parchment (10 sheets), 5 days rations, high leather boots, belt w/ belt pouch, gray robe, dark gray hooded cloak. Also carries 3 small mechanical toys: wind-up mouse, wooden puzzle cube, small jewelry box that plays a little tune.