| Ιανουάριος 1820 |
| Δε | Τρ | Τε | Πε | Πα | Σα | Κυ |
| | | | | | 1 | 2 |
| 3 | 4 | 5 | 6 | 7 | 8 | 9 |
| 10 | 11 | 12 | 13 | 14 | 15 | 16 |
| 17 | 18 | 19 | 20 | 21 | 22 | 23 |
| 24 | 25 | 26 | 27 | 28 | 29 | 30 |
| 31 | | | | | | |
| Φεβρουάριος 1820 |
| Δε | Τρ | Τε | Πε | Πα | Σα | Κυ |
| | 1 | 2 | 3 | 4 | 5 | 6 |
| 7 | 8 | 9 | 10 | 11 | 12 | 13 |
| 14 | 15 | 16 | 17 | 18 | 19 | 20 |
| 21 | 22 | 23 | 24 | 25 | 26 | 27 |
| 28 | 29 | | | | | |
| Μάρτιος 1820 |
| Δε | Τρ | Τε | Πε | Πα | Σα | Κυ |
| | | 1 | 2 | 3 | 4 | 5 |
| 6 | 7 | 8 | 9 | 10 | 11 | 12 |
| 13 | 14 | 15 | 16 | 17 | 18 | 19 |
| 20 | 21 | 22 | 23 | 24 | 25 | 26 |
| 27 | 28 | 29 | 30 | 31 | | |
| Απρίλιος 1820 |
| Δε | Τρ | Τε | Πε | Πα | Σα | Κυ |
| | | | | | 1 | 2 |
| 3 | 4 | 5 | 6 | 7 | 8 | 9 |
| 10 | 11 | 12 | 13 | 14 | 15 | 16 |
| 17 | 18 | 19 | 20 | 21 | 22 | 23 |
| 24 | 25 | 26 | 27 | 28 | 29 | 30 |
| Μάιος 1820 |
| Δε | Τρ | Τε | Πε | Πα | Σα | Κυ |
| 1 | 2 | 3 | 4 | 5 | 6 | 7 |
| 8 | 9 | 10 | 11 | 12 | 13 | 14 |
| 15 | 16 | 17 | 18 | 19 | 20 | 21 |
| 22 | 23 | 24 | 25 | 26 | 27 | 28 |
| 29 | 30 | 31 | | | | |
| Ιούνιος 1820 |
| Δε | Τρ | Τε | Πε | Πα | Σα | Κυ |
| | | | 1 | 2 | 3 | 4 |
| 5 | 6 | 7 | 8 | 9 | 10 | 11 |
| 12 | 13 | 14 | 15 | 16 | 17 | 18 |
| 19 | 20 | 21 | 22 | 23 | 24 | 25 |
| 26 | 27 | 28 | 29 | 30 | | |
| Ιούλιος 1820 |
| Δε | Τρ | Τε | Πε | Πα | Σα | Κυ |
| | | | | | 1 | 2 |
| 3 | 4 | 5 | 6 | 7 | 8 | 9 |
| 10 | 11 | 12 | 13 | 14 | 15 | 16 |
| 17 | 18 | 19 | 20 | 21 | 22 | 23 |
| 24 | 25 | 26 | 27 | 28 | 29 | 30 |
| 31 | | | | | | |
| Αύγουστος 1820 |
| Δε | Τρ | Τε | Πε | Πα | Σα | Κυ |
| | 1 | 2 | 3 | 4 | 5 | 6 |
| 7 | 8 | 9 | 10 | 11 | 12 | 13 |
| 14 | 15 | 16 | 17 | 18 | 19 | 20 |
| 21 | 22 | 23 | 24 | 25 | 26 | 27 |
| 28 | 29 | 30 | 31 | | | |
| Σεπτέμβριος 1820 |
| Δε | Τρ | Τε | Πε | Πα | Σα | Κυ |
| | | | | 1 | 2 | 3 |
| 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| 11 | 12 | 13 | 14 | 15 | 16 | 17 |
| 18 | 19 | 20 | 21 | 22 | 23 | 24 |
| 25 | 26 | 27 | 28 | 29 | 30 | |
| Οκτώβριος 1820 |
| Δε | Τρ | Τε | Πε | Πα | Σα | Κυ |
| | | | | | | 1 |
| 2 | 3 | 4 | 5 | 6 | 7 | 8 |
| 9 | 10 | 11 | 12 | 13 | 14 | 15 |
| 16 | 17 | 18 | 19 | 20 | 21 | 22 |
| 23 | 24 | 25 | 26 | 27 | 28 | 29 |
| 30 | 31 | | | | | |
| Νοέμβριος 1820 |
| Δε | Τρ | Τε | Πε | Πα | Σα | Κυ |
| | | 1 | 2 | 3 | 4 | 5 |
| 6 | 7 | 8 | 9 | 10 | 11 | 12 |
| 13 | 14 | 15 | 16 | 17 | 18 | 19 |
| 20 | 21 | 22 | 23 | 24 | 25 | 26 |
| 27 | 28 | 29 | 30 | | | |
| Δεκέμβριος 1820 |
| Δε | Τρ | Τε | Πε | Πα | Σα | Κυ |
| | | | | 1 | 2 | 3 |
| 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| 11 | 12 | 13 | 14 | 15 | 16 | 17 |
| 18 | 19 | 20 | 21 | 22 | 23 | 24 |
| 25 | 26 | 27 | 28 | 29 | 30 | 31 |
Αργίες 1820
- 1/1 Πρωτοχρονιά
- 6/1 Άγια Θεοφάνεια
- 21/2 Καθαρά Δευτέρα
- 25/3 Επανάσταση του 1821
- 7/4 Μεγάλη Παρασκευή
- 9/4 Πάσχα
- 10/4 Δευτέρα του Πάσχα
- 1/5 Εργατική Πρωτομαγιά
- 28/5 Πεντηκοστή
- 29/5 Αγίου Πνεύματος
- 15/8 Κοίμηση Θεοτόκου
- 28/10 Επέτειος του Όχι
- 17/11 Πολυτεχνείο
- 25/12 Χριστούγεννα
- 26/12 Σύναξη Θεοτόκου
