The world of the Forgotten Realms uses the Calendar of Harptos, named after the long-dead wizard who invented it. Each year of 365 days is divided into twelve months of thirty days each, which roughly correspond to months in the real-world Gregorian calendar. Each month is divided into three tendays. Five special holidays fall between the months and mark the seasons. Another special holiday, Shieldmeet, is inserted into the calendar after Midsummer every four years, much like leap years in the modern Gregorian calendar.
Dalereckoning (DR) is the most common year measurement.
| Month | Name | Common Name |
| 1 | Hammer | Deepwinter |
| Midwinter Holiday | ||
| 2 | Alturiak | The Claw of Winter |
| 3 | Ches | The Claw of the Sunsets |
| 4 | Tarsakh | The Claw of the Storms |
| Greengrass Holiday | ||
| 5 | Mirtul | The Melting |
| 6 | Kythorn | The Time of Flowers |
| 7 | Flamerule | Summertide |
| Midsummer Holiday | ||
| Shieldmeet (every four years) | ||
| 8 | Eleasias | Highsun |
| 9 | Eleint | The Fading |
| Highharvesttide Holiday | ||
| 10 | Marpenoth | Leaffall |
| 11 | Uktar | The Rotting |
| The Feast of the Moon | ||
| 12 | Nightal | The Drawing Down |