Miti

Converts between English (AD) and Nepali (BS) dates. Includes a CLI app, Rails helpers (date picker, calendar, model concern), and full Rails integration.

$ gem install miti

Or add to your Gemfile:

$ bundle add miti

All date arguments must be in YYYY-MM-DD or YYYY/MM/DD format.

$ miti today
# [2082-01-15 BS] Baisakh 15, 2082 Wednesday
# [2025-04-28 AD] April 28, 2025 Monday

$ miti to_bs 2025-04-28
# [2082-01-15 BS] Baisakh 15, 2082 Wednesday

$ miti to_ad 2082-01-15
# [2025-04-28 AD] April 28, 2025 Monday

$ miti next
# 17 days left until 1st Jestha
# Current month's last date => 31 Baisakh

require "miti"

Miti.to_bs("2025-04-28")
#=> #<Miti::NepaliDate:0x... @barsa=2082, @mahina=1, @gatey=15>

Miti.to_bs("2025-04-28").descriptive
#=> "Baisakh 15, 2082 Wednesday"

Miti.to_bs("2025-04-28").descriptive(nepali: true)
#=> "बैशाख 15, 2082 Wednesday(बुधबार)"

Miti.to_bs("2025-04-28").to_s
#=> "2082-01-15"

Miti.to_bs("2025-04-28").format("%g %b %m")
#=> "15 2082 01"

Miti.to_bs("2025-04-28").format("%B %g, %Y %A")
#=> "Baisakh 15, 2082 Wednesday"

Miti.to_bs("2025-04-28").format("%B %g, %Y %A", nepali: true)
#=> "बैशाख 15, 2082 बुधबार"

Miti.to_ad("2082-01-15")
#=> #<Date: 2025-04-28 ...>

$ rails generate miti:install

To copy styles into your app for customization:

$ rails generate miti:install --copy-styles

To undo: rails destroy miti:install

<%= form.nepali_date_field :happened_on %>
<!-- readonly text input with calendar icon that opens a month/year picker popover -->
<!-- submits as event[happened_on] — no _bs suffix needed -->

With a default value:

<%= form.nepali_date_field :happened_on, value: "2082-01-15" %>

<%= form.nepali_date_field :happened_on, theme: :dark %>
<%= form.nepali_date_field :happened_on, theme: :tokyo_night %>

Available themes: light (default), dark, indigo, midnight, tokyo_night, nord.

Use data-miti-theme on any ancestor to style a group of pickers:

<div data-miti-theme="dark">
  <%= form.nepali_date_field :start_date %>
  <%= form.nepali_date_field :end_date %>
</div>

Dark mode auto-detects prefers-color-scheme: dark. Set data-miti-theme-auto="false" on any ancestor to disable:

<div data-miti-theme-auto="false">
  <%= form.nepali_date_field :happened_on %>
</div>

<%= form.nepali_date_range_field :start_date, :end_date %>
<!-- Single clickable input + two hidden inputs; drag-to-select or click-to-select range -->

With defaults:

<%= form.nepali_date_range_field :start_date, :end_date,
      start_value: "2082-01-15", end_value: "2082-02-10" %>

Without a form builder:

<%= nepali_date_range_field :event, :start_date, :end_date %>

The display shows a friendly range like "Baisakh 15 – Jestha 3, 2082". Opens a single popover with drag-to-select. Fires miti:range-selected custom event on selection.

Options: theme, start_value, end_value, trigger_html.

<%= form.nepali_date_select :happened_on %>
<!-- renders year, month, day select elements -->

class Event < ApplicationRecord
  include Miti::Rails::ModelConcern
  has_nepali_date :happened_on
end

This defines:

• event.happened_on_bs — returns BS date as Miti::NepaliDate
• event.happened_on_bs = "2082-01-15" — sets the AD column from a BS string
• event.happened_on_bs_human — readable description (respects I18n.locale)
• event.happened_on = "2083-01-15" — auto-converts BS string to AD via custom type

class Event < ApplicationRecord
  include Miti::Rails::ModelConcern
  has_nepali_date :happened_on, store_bs: true
end

The setter writes the BS string to the happened_on_bs column on assignment. Generate the migration:

$ rails generate miti:store_bs Event happened_on

With store_bs: true:

• event.happened_on_bs reads from the DB column directly (zero conversion cost)
• Falls back to converting from AD if the column is empty
• The setter writes the BS string to the column immediately

<%= nepali_calendar(year: 2082, month: 1) do |day| %>
  <%= day.gatey %>
<% end %>

Renders a monthly grid with Turbo Frame navigation.

<%= nepali_calendar_agenda(start_date, end_date, group_by: :week) do |day| %>
  <%= day.descriptive %>
<% end %>

Renders a grouped list of dates.

Yielded to calendar/agenda blocks:

Supports Ruby 3.1 through 4.x. Rails integration loads automatically when Rails is defined.

$ bin/setup
$ bundle exec rake spec
$ bin/console

Bug reports and pull requests are welcome at github.com/xkshitizx/miti.

The gem is available as open source under the terms of the MIT License.