Week 51, 2031

Week 51 of 2031

ISO week 51 of 2031 (2031-W51) runs Monday, December 15, 2031 through Sunday, December 21, 2031. The full range is Dec 15 – Dec 21, 2031. Days follow the ISO Monday–Sunday convention. The US week label for dates in this window is 51–52.

Federal holidays in this window: No federal holidays. This week stays within a single calendar year. When a holiday shifts observance to a nearby weekday, the table shows the date offices actually close rather than the legal calendar date alone.

ISO vs US week labels

ISO weeks always start on Monday and end on Sunday. US week numbers on this site often follow a Sunday-start convention used in retail and broadcast schedules. Both labels appear on week pages so you can match internal reports that use either system. When the two disagree at year boundaries, the cross-year note on this page explains which label applies to each calendar day.

Day-by-day breakdown

The grid above lists all seven days with weekday names, calendar dates, and day-of-year numbers. That layout helps compare ISO week boundaries against month-end billing cycles or school weeks that start on Sunday. Each row links back to the parent year table for context. Payroll teams often map ISO weeks to pay periods even when checks are issued on a different weekday schedule.

Download an ICS calendar file for this week to import the date range into Outlook, Google Calendar, or Apple Calendar. The file contains one all-day event spanning Monday, December 15, 2031 through Sunday, December 21, 2031.

Navigate weeks and years

Use previous week and next week links to step through 2031 one ISO week at a time. Open the full 2031 week table to jump to any week number directly.

Printable yearly view

For a single sheet with all twelve months and week columns, download the 2031 yearly calendar PDF. Monthly detail with larger day cells is available from the monthly calendars hub when this week spans two different months.