Cyber Monday itself is officially a one-day event that runs for 24 hours on the Monday after Thanksgiving, typically from just after midnight to 11:59 p.m. local time.

Quick Scoop

Most shoppers now treat Cyber Monday as part of a longer online sale window rather than a strict one-day sale.

Official Length

  • Traditionally, Cyber Monday is defined as a single day of online deals on the Monday immediately following Black Friday.
  • Many retailers still market “Cyber Monday” as ending at 11:59 p.m. on that Monday, especially in their fine print and countdown timers.

Cyber Week: The Real Trend

  • A lot of major stores extend Cyber Monday offers into “Cyber Week,” with deals running from Monday through at least Friday, and in some cases through the following Sunday.
  • Some brands launch early “Cyber Monday” prices over the weekend before, or roll existing Black Friday deals straight into Monday and beyond, so the practical discount window can span 3–7 days.

Region and Retailer Differences

  • In the U.S., Cyber Monday is strictly the Monday after Thanksgiving by definition, but the duration of deals varies by retailer (from 24 hours to a full week).
  • In parts of Europe (like the UK, France, Portugal, and Germany), “Cyber Monday” promotions can officially run as multi-day or even eight-day sales, from the last Monday in November to the first Monday in December.

What This Means For You

  • If you want the very best or most heavily advertised online deals, plan to shop on Monday itself, especially early in the day for limited-stock items.
  • If you miss Monday, you usually still have a good chance to find similar discounts during the rest of Cyber Week, though some flash sales and doorbusters will be gone.

TL;DR: Cyber Monday “officially” lasts one day, but in practice many stores stretch it into Cyber Week, so the real deal period often runs several days around that Monday.

Information gathered from public forums or data available on the internet and portrayed here.