Time & Subdivisions

MythTapestry tracks time within a day separately from the calendar date. This page explains how to define your world’s time system — whether that’s a standard 24-hour clock, a nautical watch system, or something entirely original — and how time displays in the app.

Subdivision scales

Time within a day is defined using subdivision scales — a special type of temporal scale that works inside a single day rather than across days or years. Each subdivision scale has a name, and you specify how many of it fit into its parent.

Property	Description
Name	What you call this unit (e.g. “Hour”, “Bell”, “Deciday”, “Watch”)
Units per parent	How many of this unit fit into one parent unit (e.g. 24 hours per day, 60 minutes per hour)
Parent scale	The scale this one sits beneath (the top-level subdivision’s parent is the day itself)

You can nest as many levels as you need. The structure is entirely up to you.

Example: Standard clock time

Hour — 24 per day
  └── Minute — 60 per hour
        └── Second — 60 per minute

Example: Fantasy bell system

Bell — 8 per day  (each bell = 3 hours)
  └── Quarter — 4 per bell  (each quarter = 45 minutes)

Example: Decimal time

Deciday — 10 per day
  └── Centidecday — 100 per deciday

Any structure works — just specify the name and how many fit in the parent at each level.

The time picker

Open the calendar picker from a date field and you’ll find a Time section under the date. It shows one input per subdivision scale, from the largest unit to the smallest: Hour, then Minute. Fill in the values and confirm, and MythTapestry works out the rest.

Say the Siege of Aldmere began at dawn on 14 March 1205: pick the day, set Hour 6 and Minute 0, and the entity’s page reads the moment in your calendar’s words, “1205-03-14 at Hour 6, Minute 0”, or through a format of yours that names the time (see How time displays). When you open the picker again, it starts on the time you saved.

You can give a time wherever you enter a world date, as long as your calendar has subdivisions:

an entity’s date fields, and the Started and Ended dates of a relationship you set through one of its fields;
a relationship’s Valid From and Valid To (Creating Relationships);
a world event’s start and end;
each date in a content unit’s When does this happen? panel, and a container’s date-and-time fields;
date chips and date links in your writing (choose With Time);
a map region’s or layer’s window, and the dates of a move on the map;
the moment you view the graph or your world at (Graph View).

A few things worth knowing:

Empty means no time. Leave every time input empty and the date stays day-only. On an entity’s date field, exactly 00:00 is saved the same way, because there the time is stored as part of the date and midnight adds nothing to it. Set 00:01 if you need to pin the very start of the day.
An empty smaller unit counts as zero. Hour 6 with Minute left empty is 06:00.
A time the day doesn’t have is refused. Ask for Hour 24 in a 24-hour day and the picker says “Hour must be a whole number from 0 to 23.” It stays open so you can fix it, and nothing is saved until you do.
The date field’s own boxes take the date only. When you switch a date field to its per-level boxes (Year, Month, Day), the time stays in the picker.

How time displays

A stored time is shown in your calendar’s own words. If your calendar has a format that names its divisions of the day, such as {Hour:value:02}:{Minute:value:02}, a date with a time reads through that format: 14:30. Otherwise MythTapestry names each level, largest first: Hour 14, Minute 30, Bell 4, Quarter 2, or just Bell 4 for a day split into bells alone. With a date, it reads 14 March 1205 at Bell 4, Quarter 2.

Nothing is hardcoded as hours, minutes or seconds; a format only counts as showing the time when it names one of your own subdivisions.

If a calendar has no subdivision scales defined, there’s no time to pick: the time boxes are hidden, and With Time in the editor’s date picker says This calendar doesn’t divide its day.

Format strings for time

Format strings work with subdivision scales using the same {ScaleName:formatter} syntax as date formatting. See Creating Calendars for the full token reference.

Example — standard 24-hour time:

{Hour:value:02}:{Minute:value:02}

Displays as: 14:30

Example — date and time together:

{Month:unit} {Day:day_ord}, {Year:value} at {Hour:value:02}:{Minute:value:02}

Displays as: January 15th, 2024 at 14:30

The padding :02 ensures single-digit values display with a leading zero (09 instead of 9).

Custom time system examples

Watches at sea

A nautical fantasy world might track time in watches:

Watch — 4 per day
  └── Glass — 8 per watch  (~30 minutes each)

This gives timestamps like “3rd glass of the morning watch” — fully supported with the same date picker and display as any other time system.

Imperial decimal beats

A world with decimal calendars might pair them with decimal time:

Beat — 10 per day  (each beat = 2.4 standard hours)
  └── Microbeat — 1000 per beat  (~8.64 seconds each)

Single-level time

If your world only needs broad time-of-day references with no finer divisions:

Bell — 12 per day

The picker shows one field, and a time reads as Bell 7.