Calendar cookbook

Concrete recipes for the calendar shapes that come up most. Each recipe is a starting point — fork from the closest template, then edit.

Gregorian (real-world)

The built-in fallback. If your campaign is in the real world or a real-world-adjacent setting, you don’t need to do anything — events authored without a specific calendar show as Gregorian.

If you want the Gregorian template explicitly (for Settings → Calendars → +), it ships with:

• 12 named months (January through December).
• 7 weekdays (Monday through Sunday).
• Single CE era starting at year 1.
• 4/100/400 leap cycle adding a day to February.
• Epoch year 1970, Epoch ISO 1970-01-01.

Harptos (Forgotten Realms)

The classic D&D calendar. Twelve months of exactly 30 days, 10-day tenday week, five named feast days as intercalary, and Shieldmeet appearing every fourth year.

• Months — Hammer, Alturiak, Ches, Tarsakh, Mirtul, Kythorn, Flamerule, Eleasis, Eleint, Marpenoth, Uktar, Nightal. All 30 days each.
• Weekdays — 10-day tenday. The template names them generically (Day 1 through Day 10) — rename to your taste if your setting uses specific names.
• Eras — DR (Dale Reckoning) starting at year 1. Add others as needed.
• Intercalary days — Midwinter (after Hammer 30), Greengrass (after Tarsakh 30), Midsummer (after Flamerule 30), Shieldmeet (after Flamerule 30, leap-only), Highharvestide (after Eleint 30), Feast of the Moon (after Uktar 30).
• Leap rules — every 4 years, adding the Shieldmeet feast day.

The template clones all of this in one click.

Exandria (Calendar of the Tal’Dorei)

Critical Role / Tal’Dorei calendar. Eleven months of varying length, 7-day week, ~328-day year. Build from Blank:

• Months — Horisal (29), Misuthar (30), Dualahei (30), Thunsheer (31), Unndilar (28), Brussendar (31), Sydenstar (32), Fessuran (29), Quen’pillar (27), Cuersaar (29), Duscar (32). Total 328 days.
• Weekdays — 7-day week. The Tal’Dorei calendar names them Miresen, Grissen, Whelsen, Conthsen, Folsen, Yulisen, Da’leysen.
• Eras — PD (Post-Divergence) starting at year 1, Pre-Divergence starting at year -812 (use a year offset if you want reverse counting).

No leap rules in canonical Exandria, so leave the leap rules empty.

Four Seasons

For poetic / pastoral worlds where time tracks by season, not month.

• Months — Spring (91), Summer (92), Autumn (91), Winter (91). 365 total.
• Weekdays — empty array. (Or 7-day if you still want them.)
• Eras — single era starting at year 1.
• Display format — {day} of {monthName}, {year} {yearLabelShort} → “12 of Spring, 47 AS”.

Campaign Days

For session-only campaigns where in-world dates don’t matter.

• Months — a single month called “Day”, with a length of 99999.
• Weekdays — empty.
• Eras — empty.
• Display format — Day {year} → “Day 42”.

Or skip a custom calendar entirely and use session precision on every event.

Regnal years

When years count from a monarch’s accession instead of a fixed epoch — “Year 12 of the Reign of Mira”.

Build off Blank and use eras for each reign:

• One era per monarch. Each era’s start year is the year of accession. Set the year offset to the start year minus 1 so the year number resets.
• Each era’s year format is Year {year_in_era} of the {eraName} or similar.

Example: Aldren reigned from year 1235 to 1247; Mira from 1247 onwards. Two eras:

• Reign of Aldren: start year 1235, year offset 1234, year format Year {year_in_era} of the {eraName}.
• Reign of Mira: start year 1247, year offset 1246.

An event in year 1240 reads as “Year 6 of the Reign of Aldren”; year 1259 reads as “Year 13 of the Reign of Mira”. An event’s position on the master timeline keeps marching forward; the year number visually resets at each accession.

Post-apocalyptic “After the Fall”

A single-era calendar with year-only display.

• Months — keep the Gregorian list, or use the Four Seasons.
• Eras — single era AF (After the Fall) at year 1.
• Display format — {year} {yearLabelShort} → “127 AF”.
• Year label (short) — “AF”.

Optionally pair with a Before the Fall era at year -1 (or 1 with a negative year offset) to show “BF” for events before the fall.

Lunar

A calendar where months track the moon — 13 × 28 = 364 days.

• Months — 13 lunar months, each 28 days. Name them after moons if your setting has named moons, or numerically.
• Weekdays — 7-day week (or 4-day if you want 4 weeks per moon).
• Pair with a moon cycle whose Period (minutes) is 28 * 24 * 60 so the moon phase chips align exactly with month boundaries.

Tip

After building any calendar, switch to the Calendar tab, pick it as the Display calendar, and step through a few months to make sure intercalary days, weekday alignment, and era boundaries look right. Easier to fix issues now than after authoring 50 events against it.

Related

• Building a calendar — the editor walkthrough
• Eras and regnal years — deep era model
• Multiple calendars — Harptos + Gregorian side by side