Editing Friday the 13th (section)

==== Frequency within a single year ====
There can be no more than three Friday the 13ths in a single calendar year; either in February, March, and November in a [[common year starting on Thursday]] (such as 2009, 2015, or 2026) [[Dominical letter|(D)]], or January, April, and July in a [[leap year starting on Sunday]] (such as 1984, 2012, or 2040) [[Dominical letter|(AG)]].<ref name=Kher-13Facts-TaD>{{cite web |first=Aparna |last=Kher |title=13 Facts about Friday the 13th |website=Time and Date (timeanddate.com) |url=https://www.timeanddate.com/calendar/13-things-friday-13.html}}</ref>

In the 2000s, there were three Friday the 13ths in 2009, and two Friday the 13ths in 2001, 2002, 2006, and 2007. In the 2010s, there were three Friday the 13ths in 2012 and 2015, and two in 2013, 2017, 2018, and 2019.<ref name=Fri-13-months-days-TaD/> In the 2020s, there were two Friday the 13ths in 2020, 2023 and 2024. There will also be three Friday the 13ths in 2026, and two in 2029.<ref name=Fri-13-months-days-TaD/> The remaining years all have one Friday the 13th.<ref name=Fri-13-months-days-TaD/>

For the details see the table below; this table is for the Gregorian calendar and {{red|Jan}}/{{red|Feb}} for {{red|leap years}}:

:{| class="wikitable" style="margin-left: auto; margin-right: auto; border: none;"
|- style="vertical-align:center; text-align:center"
! Year<br/>[[modular arithmetic|modulo]] 28 || {{red|1600 2000}} || 1700 2100 || 1800 2200 || 1900 2300 || Year<br/>[[modular arithmetic|modulo]] 28
|-
| {{red|00}} 06 {{figure space}}{{figure space}} 17 23 || Jan Oct || {{red|Feb}} Aug || Jun || {{red|Jan}} Apr Jul || {{red|00}} 06 {{figure space}}{{figure space}} 17 23
|-
| 01 07 {{red|12}} 18 {{figure space}}{{figure space}} || {{red|Jan}} Apr Jul || May || Feb Mar Nov || Sep Dec || 01 07 {{red|12}} 18 {{figure space}}{{figure space}}
|-
| 02 {{figure space}}{{figure space}} 13 19 {{red|24}} || Sep Dec || Jan Oct || {{red|Feb}} Aug || Jun || 02 {{figure space}}{{figure space}} 13 19 {{red|24}}
|-
| 03 {{red|08}} 14 {{figure space}}{{figure space}} 25 || Jun || {{red|Jan}} Apr Jul || May || Feb Mar Nov || 03 {{red|08}} 14 {{figure space}}{{figure space}} 25
|-
| {{figure space}}{{figure space}} 09 15 {{red|20}} 26 || Feb Mar Nov || Sep Dec || Jan Oct || {{red|Feb}} Aug || {{figure space}}{{figure space}} 09 15 {{red|20}} 26
|-
| {{red|04}} 10 {{figure space}}{{figure space}} 21 27 || {{red|Feb}} Aug || Jun || {{red|Jan}} Apr Jul || May || {{red|04}} 10 {{figure space}}{{figure space}} 21 27
|-
| 05 11 {{red|16}} 22 {{figure space}}{{figure space}} || May || Feb Mar Nov || Sep Dec || Jan Oct || 05 11 {{red|16}} 22 {{figure space}}{{figure space}}
|}