Week numbers 2025

The week year 2025 has 52 ISO weeks. 30 December 2024 – 28 December 2025.

How many weeks are in 2025?

The ISO week-numbering year 2025 has 52 numbered weeks. The calendar year has 365 days: 52 full weeks plus 1 extra day. The table lists Monday to Sunday for each ISO week. These weeks can extend before January 1 or after December 31.

2025 at a glance

First ISO week: 30 December 2024 – 5 January 2025
Last ISO week: 22 December 2025 – 28 December 2025
January 1: Week 01 / 2025
December 31: Week 01 / 2026
Days in the calendar year: 365

Why 52 numbered weeks?

2025 does not meet the condition for 53 ISO weeks: January 1 would need to be a Thursday, or a Wednesday in a leap year. This week-year therefore has 52 numbered weeks.

For dates around New Year, include the week-year alongside the week number. The assignments above explicitly show whether January 1 or December 31 belongs to a neighbouring week-year.

Choose a print layout for 2025

One page is useful for quick reference. Twelve monthly pages provide more room for handwritten appointments. The print layout includes dates and ISO weeks, not public holidays or school holidays.

Calendar guide & sources

Full-year calendar with every day

W	From (Mon)	To (Sun)
01	30/12 2024	05/01
02	06/01	12/01
03	13/01	19/01
04	20/01	26/01
05	27/01	02/02
06	03/02	09/02
07	10/02	16/02
08	17/02	23/02
09	24/02	02/03
10	03/03	09/03
11	10/03	16/03
12	17/03	23/03
13	24/03	30/03
14	31/03	06/04
15	07/04	13/04
16	14/04	20/04
17	21/04	27/04
18	28/04	04/05

W	From (Mon)	To (Sun)
19	05/05	11/05
20	12/05	18/05
21	19/05	25/05
22	26/05	01/06
23	02/06	08/06
24	09/06	15/06
25	16/06	22/06
26	23/06	29/06
27	30/06	06/07
28	07/07	13/07
29	14/07	20/07
30	21/07	27/07
31	28/07	03/08
32	04/08	10/08
33	11/08	17/08
34	18/08	24/08
35	25/08	31/08
36	01/09	07/09

W	From (Mon)	To (Sun)
37	08/09	14/09
38	15/09	21/09
39	22/09	28/09
40	29/09	05/10
41	06/10	12/10
42	13/10	19/10
43	20/10	26/10
44	27/10	02/11
45	03/11	09/11
46	10/11	16/11
47	17/11	23/11
48	24/11	30/11
49	01/12	07/12
50	08/12	14/12
51	15/12	21/12
52	22/12	28/12

ISO 8601 · calendarweek.world

What happens at New Year?

Early January can belong to the previous week year. Late December can already belong to week 1 of the next week year. Dates outside the calendar year include their year in the table.

Other year calendars

Data accuracy and liability

All calendar, public-holiday and school-holiday information is for general guidance. We do not guarantee its accuracy, completeness or timeliness. Regional, local and school-specific differences and short-notice changes are possible. Confirm binding dates with the relevant authority, municipality or school before making plans. Liability for losses arising from use of this information is excluded to the extent permitted by law. Mandatory statutory liability remains unaffected.