Common year starting on Monday

A common year starting on Monday is any non-leap year (i.e., a year with 365 days) that begins on Monday, 1 January, and ends on Monday, 31 December. Its dominical letter hence is G. The most recent year of such kind was 2018, and the next one will be 2029 in the Gregorian calendar, or likewise, 2019 and 2030 in the Julian calendar, see below for more. This common year is one of the three possible common years in which a century year can begin on and occurs in century years that yield a remainder of 300 when divided by 400. The most recent such year was 1900, and the next one will be 2300.

Any common year that starts on Monday has two Friday the 13ths: those two in this common year occur in April and July.[globalize] From July of the year in this type of year to September in the year that follows this type of year is the longest period that occurs without a Friday the 13th, unless the following year is a leap year starting on Tuesday, in which case the gap only 11 months, as the next Friday the 13th is already in June.

This type of year has three instances of Tuesday the 13th: in February, March and November. Leap years starting on Thursday have this characteristic in January, April and July.

This year has four months (April, July, September and December) which begin on a weekend-day.

Calendars

Calendar for any common year starting on Monday,
presented as common in many English-speaking areas
January
SuMoTuWeThFrSa
123456
78910111213
14151617181920
21222324252627
28293031 
 
February
SuMoTuWeThFrSa
123
45678910
11121314151617
18192021222324
25262728
 
March
SuMoTuWeThFrSa
123
45678910
11121314151617
18192021222324
25262728293031
 
April
SuMoTuWeThFrSa
1234567
891011121314
15161718192021
22232425262728
2930 
 
May
SuMoTuWeThFrSa
12345
6789101112
13141516171819
20212223242526
2728293031 
 
June
SuMoTuWeThFrSa
12
3456789
10111213141516
17181920212223
24252627282930
 
July
SuMoTuWeThFrSa
1234567
891011121314
15161718192021
22232425262728
293031 
 
August
SuMoTuWeThFrSa
1234
567891011
12131415161718
19202122232425
262728293031 
 
September
SuMoTuWeThFrSa
1
2345678
9101112131415
16171819202122
23242526272829
30 
October
SuMoTuWeThFrSa
123456
78910111213
14151617181920
21222324252627
28293031 
 
November
SuMoTuWeThFrSa
123
45678910
11121314151617
18192021222324
252627282930
 
December
SuMoTuWeThFrSa
1
2345678
9101112131415
16171819202122
23242526272829
3031 
ISO 8601-conformant calendar with week numbers for
any common year starting on Monday (dominical letter G)
January
WkMoTuWeThFrSaSu
0101020304050607
0208091011121314
0315161718192021
0422232425262728
05293031 
  
February
WkMoTuWeThFrSaSu
0501020304
0605060708091011
0712131415161718
0819202122232425
09262728 
  
March
WkMoTuWeThFrSaSu
0901020304
1005060708091011
1112131415161718
1219202122232425
13262728293031 
  
April
WkMoTuWeThFrSaSu
1301
1402030405060708
1509101112131415
1616171819202122
1723242526272829
1830 
May
WkMoTuWeThFrSaSu
18010203040506
1907080910111213
2014151617181920
2121222324252627
2228293031 
  
June
WkMoTuWeThFrSaSu
22010203
2304050607080910
2411121314151617
2518192021222324
26252627282930
  
July
WkMoTuWeThFrSaSu
2601
2702030405060708
2809101112131415
2916171819202122
3023242526272829
313031 
August
WkMoTuWeThFrSaSu
310102030405
3206070809101112
3313141516171819
3420212223242526
352728293031 
  
September
WkMoTuWeThFrSaSu
350102
3603040506070809
3710111213141516
3817181920212223
3924252627282930
  
October
WkMoTuWeThFrSaSu
4001020304050607
4108091011121314
4215161718192021
4322232425262728
44293031 
  
November
WkMoTuWeThFrSaSu
4401020304
4505060708091011
4612131415161718
4719202122232425
482627282930 
  
December
WkMoTuWeThFrSaSu
480102
4903040506070809
5010111213141516
5117181920212223
5224252627282930
0131 

Applicable years

Gregorian calendar

In the (currently used) Gregorian calendar, along with Sunday, Wednesday, Friday or Saturday, the fourteen types of year (seven common, seven leap) repeat in a 400-year cycle (20871 weeks). Forty-three common years per cycle or exactly 10.75% start on a Monday. The 28-year sub-cycle only spans across century years divisible by 400, e.g. 1600, 2000, and 2400.

Julian calendar

In the Julian calendar, the fourteen types of year (seven common, seven leap) repeat in a 28-year cycle (1461 weeks). This sequence occurs exactly once within a cycle, and every common letter thrice.

As the Julian calendar repeats after 28 years that means it will also repeat after 700 years, i.e. 25 cycles. The year's position in the cycle is given by the formula ((year + 8) mod 28) + 1). Years 6, 12 and 23 of the cycle are common years beginning on Monday. 2017 is year 10 of the cycle. Approximately 10.71% of all years are common years beginning on Monday.

Holidays

International

Roman Catholic Solemnities

Australia and New Zealand

British Isles

Canada

United States

References

Uses material from the Wikipedia article Common year starting on Monday, released under the CC BY-SA 4.0 license.