The Dominical Letter Calendar by Walter Ziobro is a version of the Gregorian Calendar that can be used either as a perennial calendar, or as a perpetual calendar of continuous weeks.
Each day of the year is assigned a letter of the alphabet from A to G. 01-January is always A-day, and all the rest of the days of the year are lettered in sequence, each day of the year always having the same letter name. The letters continue through 31-December, which is also an A-day. The Sequence recommences with A-day on 01-January of the year following. 29-February (leap day) does not have a dominical letter.
An example of the calendar is shown below. To use it as a perennial calendar, simply call each day of the week by the dominical letter of that calendar date. To use it as a perpetual calendar of continuous weeks, scroll down to the end of the calendar to find a table which assigns the traditional, continuous weekday names that correspond to the dominical letter of any year. Just remember that in leap year the dominical letter of the year moves to the preceding letter of the alphabet.
| Week | A-day | B-day | C-day | D-day | E-day | F-day | G-day |
|---|---|---|---|---|---|---|---|
| 01 | 01-Jan | 02-Jan | 03-Jan | 04-Jan | 05-Jan | 06-Jan | 07-Jan |
| 02 | 08-Jan | 09-Jan | 10-Jan | 11-Jan | 12-Jan | 13-Jan | 14-Jan |
| 03 | 15-Jan | 16-Jan | 17-Jan | 18-Jan | 19-Jan | 20-Jan | 21-Jan |
| 04 | 22-Jan | 23-Jan | 24-Jan | 25-Jan | 26-Jan | 27-Jan | 28-Jan |
| 05 | 29-Jan | 30-Jan | 31-Jan | 01-Feb | 02-Feb | 03-Feb | 04-Feb |
| 06 | 05-Feb | 06-Feb | 07-Feb | 08-Feb | 09-Feb | 10-Feb | 11-Feb |
| 07 | 12-Feb | 13-Feb | 14-Feb | 15-Feb | 16-Feb | 17-Feb | 18-Feb |
| 08 | 19-Feb | 20-Feb | 21-Feb | 22-Feb | 23-Feb | 24-Feb | 25-Feb |
| 09 | 26-Feb | 27-Feb | 28-Feb | 01-Mar | 02-Mar | 03-Mar | 04-Mar |
| 10 | 05-Mar | 06-Mar | 07-Mar | 08-Mar | 09-Mar | 10-Mar | 11-Mar |
| 11 | 12-Mar | 13-Mar | 14-Mar | 15-Mar | 16-Mar | 17-Mar | 18-Mar |
| 12 | 19-Mar | 20-Mar | 21-Mar | 22-Mar | 23-Mar | 24-Mar | 25-Mar |
| 13 | 26-Mar | 27-Mar | 28-Mar | 29-Mar | 30-Mar | 31-Mar | 01-Apr |
| 14 | 02-Apr | 03-Apr | 04-Apr | 05-Apr | 06-Apr | 07-Apr | 08-Apr |
| 15 | 09-Apr | 10-Apr | 11-Apr | 12-Apr | 13-Apr | 14-Apr | 15-Apr |
| 16 | 16-Apr | 17-Apr | 18-Apr | 19-Apr | 20-Apr | 21-Apr | 22-Apr |
| 17 | 23-Apr | 24-Apr | 25-Apr | 26-Apr | 27-Apr | 28-Apr | 29-Apr |
| 18 | 30-Apr | 01-May | 02-May | 03-May | 04-May | 05-May | 06-May |
| 19 | 07-May | 08-May | 09-May | 10-May | 11-May | 12-May | 13-May |
| 20 | 14-May | 15-May | 16-May | 17-May | 18-May | 19-May | 20-May |
| 21 | 21-May | 22-May | 23-May | 24-May | 25-May | 26-May | 27-May |
| 22 | 28-May | 29-May | 30-May | 31-May | 01-Jun | 02-Jun | 03-Jun |
| 23 | 04-Jun | 05-Jun | 06-Jun | 07-Jun | 08-Jun | 09-Jun | 10-Jun |
| 24 | 11-Jun | 12-Jun | 13-Jun | 14-Jun | 15-Jun | 16-Jun | 17-Jun |
| 25 | 18-Jun | 19-Jun | 20-Jun | 21-Jun | 22-Jun | 23-Jun | 24-Jun |
| 26 | 25-Jun | 26-Jun | 27-Jun | 28-Jun | 29-Jun | 30-Jun | 01-Jul |
| 27 | 02-Jul | 03-Jul | 04-Jul | 05-Jul | 06-Jul | 07-Jul | 08-Jul |
| 28 | 09-Jul | 10-Jul | 11-Jul | 12-Jul | 13-Jul | 14-Jul | 15-Jul |
| 29 | 16-Jul | 17-Jul | 18-Jul | 19-Jul | 20-Jul | 21-Jul | 22-Jul |
| 30 | 23-Jul | 24-Jul | 25-Jul | 26-Jul | 27-Jul | 28-Jul | 29-Jul |
| 31 | 30-Jul | 31-Jul | 01-Aug | 02-Aug | 03-Aug | 04-Aug | 05-Aug |
| 32 | 06-Aug | 07-Aug | 08-Aug | 09-Aug | 10-Aug | 11-Aug | 12-Aug |
| 33 | 13-Aug | 14-Aug | 15-Aug | 16-Aug | 17-Aug | 18-Aug | 19-Aug |
| 34 | 20-Aug | 21-Aug | 22-Aug | 23-Aug | 24-Aug | 25-Aug | 26-Aug |
| 35 | 27-Aug | 28-Aug | 29-Aug | 30-Aug | 31-Aug | 01-Sep | 02-Sep |
| 36 | 03-Sep | 04-Sep | 05-Sep | 06-Sep | 07-Sep | 08-Sep | 09-Sep |
| 37 | 10-Sep | 11-Sep | 12-Sep | 13-Sep | 14-Sep | 15-Sep | 16-Sep |
| 38 | 17-Sep | 18-Sep | 19-Sep | 20-Sep | 21-Sep | 22-Sep | 23-Sep |
| 39 | 24-Sep | 25-Sep | 26-Sep | 27-Sep | 28-Sep | 29-Sep | 30-Sep |
| 40 | 01-Oct | 02-Oct | 03-Oct | 04-Oct | 05-Oct | 06-Oct | 07-Oct |
| 41 | 08-Oct | 09-Oct | 10-Oct | 11-Oct | 12-Oct | 13-Oct | 14-Oct |
| 42 | 15-Oct | 16-Oct | 17-Oct | 18-Oct | 19-Oct | 20-Oct | 21-Oct |
| 43 | 22-Oct | 23-Oct | 24-Oct | 25-Oct | 26-Oct | 27-Oct | 28-Oct |
| 44 | 29-Oct | 30-Oct | 31-Oct | 01-Nov | 02-Nov | 03-Nov | 04-Nov |
| 45 | 05-Nov | 06-Nov | 07-Nov | 08-Nov | 09-Nov | 10-Nov | 11-Nov |
| 46 | 12-Nov | 13-Nov | 14-Nov | 15-Nov | 16-Nov | 17-Nov | 18-Nov |
| 47 | 19-Nov | 20-Nov | 21-Nov | 22-Nov | 23-Nov | 24-Nov | 25-Nov |
| 48 | 26-Nov | 27-Nov | 28-Nov | 29-Nov | 30-Nov | 01-Dec | 02-Dec |
| 49 | 03-Dec | 04-Dec | 05-Dec | 06-Dec | 07-Dec | 08-Dec | 09-Dec |
| 50 | 10-Dec | 11-Dec | 12-Dec | 13-Dec | 14-Dec | 15-Dec | 16-Dec |
| 51 | 17-Dec | 18-Dec | 19-Dec | 20-Dec | 21-Dec | 22-Dec | 23-Dec |
| 52 | 24-Dec | 25-Dec | 26-Dec | 27-Dec | 28-Dec | 29-Dec | 30-Dec |
| 53 | 31-Dec |
| DL | A-Day | B-Day | C-Day | D-Day | E-Day | F-Day | G-Day |
|---|---|---|---|---|---|---|---|
| A | Sun | Mon | Tue | Wed | Thu | Fri | Sat |
| B | Sat | Sun | Mon | Tue | Wed | Thu | Fri |
| C | Fri | Sat | Sun | Mon | Tue | Wed | Thu |
| D | Thu | Fri | Sat | Sun | Mon | Tue | Wed |
| E | Wed | Thu | Fri | Sat | Sun | Mon | Tue |
| F | Tue | Wed | Thu | Fri | Sat | Sun | Mon |
| G | Mon | Tue | Wed | Thu | Fri | Sat | Sun |