The best time to see Kathleen Little's work, filmed over eight Saturday nights in Glasgow, is Sunday morning. Shown in the window of Bulkhead's headquarters, on the city's High Street in the east end, the videos play on silently, even though the window has suffered the slings and arrows of outrageous drunkenness and partying the night before.

A dark red liquid is smeared across the pane: it could be blood, or ketchup detached from its chips. A pile of loose change is stacked with inexplicable neatness between pools of vomit stretched out on the pavement. None of these extras are Little's doing, but it's impossible to detach a work shown in a 24-hour window onto the street from the life lived around it.

On screen, anonymous characters perform rituals associated with Saturday night. Asked by Little to engage with the camera for three minutes without speaking, the films record moments in a pub, club, bookshop, Central station, a gym and an accident and emergency ward. In the club setting, a couple swig from beer bottles, grin madly and then snog with a marked sense of urgency. They do it all again as other clubbers pass by; nobody looks at them especially. The screen fades.

The next pair, two women in their early 20s, attract far more attention. Their ritual is to blow huge pink bubbles with the gum they are sulkily chewing. Competitiveness (they blow together, eyeing each other to see who has the biggest bubble) gives way to respect as the winner gets a nod of approval from the other. Clubbers who pass, meanwhile, are treated to a mean, sarcastic glare.

This is what Little captures so well: the private worlds and codes that make up the bigger picture of a Saturday night. Presenting these worlds silently lends the work an edge, makes the horribly familiar strange. Best of all - and this goes for all of Bulkhead's work shown in public spaces across the city - the 24-hour window is a genuinely demystifying tactic. On a street that forms an informal boundary between the refurbished Merchant City and the east end, the window breaks down that barrier between life as it is lived and the precious space of the gallery. The work in the window is free and easy to engage with - a cross between watching television and window-shopping - whatever time on a Saturday night you might be passing by.

Until 13 January. Details: www.bulkhead.org.uk