Big Brother seasons vary in length by country and edition, but most U.S. and international versions run roughly 2.5 to 3.5 months per season. Here are representative durations to set expectations:

• United States (Big Brother US): Typical seasons last about 90 to 100 days, with recent seasons clustering around 90–100 days. The finale is usually a live 60–120 minute event, often on Sundays, depending on the schedule for that year.

• United Kingdom (Big Brother UK): Historically longer early series ran around 70–90 days, with variations across the 2000s; more recent formats have shortened or altered the pacing, but seasons commonly fall in the 60–90 day range.

• Australia (Big Brother Australia): Recent revivals have targeted shorter seasons, often around 4 weeks (28 days) to roughly 50 days depending on the edition. The latest relaunches have aimed for concise runtimes.

• Celebrity or special editions: These are typically much shorter, often around 2–4 weeks (14–28 days). Examples include Celebrity Big Brother variants that run for about 19 days.

If you’re asking about a specific country or season, I can give the exact duration for that edition. For the most current season, durations are announced by the network ahead of premiere and can shift slightly due to scheduling decisions.