A Rails helper gem to display time differences in a human-readable format with automatic updates.

Add this line to your application's Gemfile:

gem 'rails-diff-time'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install rails-diff-time

No setup required! Just install the gem and start using it. The auto-update JavaScript will be automatically included when you use auto_update: true for the first time on a page.

In your Rails views, you can use the diff_time helper to display time differences:

<%= diff_time(Time.now + 3.days) %>
# Output: <span>3 days later</span>

<%= diff_time(Time.now - 2.hours) %>
# Output: <span>2 hours ago</span>

<%= diff_time(Time.now + 1.year + 2.months, "div", { class: "time-diff" }) %>
# Output: <div class="time-diff">1 year 2 months later</div>

Enable automatic updates (every 1 minute) by passing the auto_update: true option:

<%= diff_time(user.created_at, auto_update: true) %>
# The display will automatically update every minute

<%= diff_time(post.published_at, "span", { class: "timestamp" }, auto_update: true) %>
# With custom element and attributes

Note: The necessary JavaScript code will be automatically included on the page the first time you call diff_time with auto_update: true. No manual setup required!

diff_time(certain_time, element_name = "span", attributes = {}, auto_update: false)

• certain_time (required): The time to compare with the current time
• element_name (optional, default: "span"): The HTML element to wrap the output
• attributes (optional, default: {}): HTML attributes to add to the element
• auto_update (optional, default: false): Enable automatic updates every minute (JavaScript automatically included on first use)

# Simple usage
<%= diff_time(user.created_at) %>

# Custom element
<%= diff_time(event.starts_at, "p") %>

# With CSS classes
<%= diff_time(post.published_at, "span", { class: "text-muted", id: "post-time" }) %>

# With auto-update enabled (JavaScript automatically included)
<%= diff_time(meeting.scheduled_at, "span", { class: "meeting-time" }, auto_update: true) %>

# Live timestamps for comments
<% @comments.each do |comment| %>
  <div class="comment">
    <p><%= comment.body %></p>
    <small>Posted <%= diff_time(comment.created_at, auto_update: true) %></small>
  </div>
<% end %>

app/views/posts/show.html.erb:

<article>
  <h1><%= @post.title %></h1>
  <p class="meta">
    Published <%= diff_time(@post.published_at, auto_update: true) %>
  </p>
  <div><%= @post.content %></div>
</article>

That's it! No need to modify layout files or configure JavaScript imports.

The auto-update feature works by:

1. Storing the original timestamp in a data-certain-time attribute (ISO 8601 format)
2. Automatically including JavaScript code on first use of auto_update: true
3. Running a JavaScript timer that recalculates the time difference every 60 seconds
4. Updating the text content of elements client-side

This means:

• No additional server requests are made
• The display stays accurate without page reloads
• Works with Turbolinks/Turbo for SPA-like experiences
• No JavaScript imports, asset pipeline configuration, or layout modifications needed - everything is automatic!

The JavaScript functionality requires:

• Modern browsers with ES6+ support
• Native Date object support
• setInterval support

Compatible with:

• Chrome/Edge (latest)
• Firefox (latest)
• Safari (latest)
• Mobile browsers (iOS Safari, Chrome Mobile)

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/dhq_boiler/rails-diff-time.

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