diff --git a/app/assets/javascripts/radioSelect.js b/app/assets/javascripts/radioSelect.js
index 9426c0ab4..6edfd5392 100644
--- a/app/assets/javascripts/radioSelect.js
+++ b/app/assets/javascripts/radioSelect.js
@@ -7,12 +7,14 @@
 
   let states = {
     'initial': Hogan.compile(`
-      <div class="radio-select__column">
-        <div class="multiple-choice js-multiple-choice">
-          <input checked="checked" id="{{name}}-0" name="{{name}}" type="radio" value="">
-          <label class="block-label js-block-label" for="{{name}}-0">Now</label>
+      {{#showNowAsDefault}}
+        <div class="radio-select__column">
+          <div class="multiple-choice js-multiple-choice">
+            <input checked="checked" id="{{name}}-0" name="{{name}}" type="radio" value="">
+            <label class="block-label js-block-label" for="{{name}}-0">Now</label>
+          </div>
         </div>
-      </div>
+      {{/showNowAsDefault}}
       <div class="radio-select__column">
         {{#categories}}
           <input type='button' class='govuk-button govuk-button--secondary radio-select__button--category' value='{{.}}' />
@@ -20,12 +22,14 @@
       </div>
     `),
     'choose': Hogan.compile(`
-      <div class="radio-select__column">
-        <div class="multiple-choice js-multiple-choice js-initial-option">
-          <input checked="checked" id="{{name}}-0" name="{{name}}" type="radio" value="">
-          <label for="{{name}}-0">Now</label>
+      {{#showNowAsDefault}}
+        <div class="radio-select__column">
+          <div class="multiple-choice js-multiple-choice js-initial-option">
+            <input checked="checked" id="{{name}}-0" name="{{name}}" type="radio" value="">
+            <label for="{{name}}-0">Now</label>
+          </div>
         </div>
-      </div>
+      {{/showNowAsDefault}}
       <div class="radio-select__column">
         {{#choices}}
           <div class="multiple-choice js-multiple-choice js-option">
@@ -37,12 +41,14 @@
       </div>
     `),
     'chosen': Hogan.compile(`
-      <div class="radio-select__column">
-        <div class="multiple-choice js-multiple-choice js-initial-option">
-          <input id="{{name}}-0" name="{{name}}" type="radio" value="">
-          <label for="{{name}}-0">Now</label>
+      {{#showNowAsDefault}}
+        <div class="radio-select__column">
+          <div class="multiple-choice js-multiple-choice js-initial-option">
+            <input id="{{name}}-0" name="{{name}}" type="radio" value="">
+            <label for="{{name}}-0">Now</label>
+          </div>
         </div>
-      </div>
+      {{/showNowAsDefault}}
       <div class="radio-select__column">
         {{#choices}}
           <div class="multiple-choice js-multiple-choice">
@@ -80,10 +86,15 @@
       let categories = $component.data('categories').split(',');
       let name = $component.find('input').eq(0).attr('name');
       let mousedownOption = null;
+      let showNowAsDefault = (
+        $component.data('show-now-as-default').toLowerCase() === 'true' ?
+        {'name': name} : false
+      );
       const reset = () => {
         render('initial', {
           'categories': categories,
-          'name': name
+          'name': name,
+          'showNowAsDefault': showNowAsDefault
         });
       };
       const selectOption = (value) => {
@@ -91,7 +102,8 @@
           'choices': choices.filter(
             element => element.value == value
           ),
-          'name': name
+          'name': name,
+          'showNowAsDefault': showNowAsDefault
         });
         focusSelected(component);
       };
@@ -153,7 +165,8 @@
               'choices': choices.filter(
                 element => element.value == $selection.eq(0).attr('value')
               ),
-              'name': name
+              'name': name,
+              'showNowAsDefault': showNowAsDefault
             });
 
           } else {
@@ -174,7 +187,8 @@
 
       render('initial', {
         'categories': categories,
-        'name': name
+        'name': name,
+        'showNowAsDefault': showNowAsDefault
       });
 
       $component.css({'height': 'auto'});
diff --git a/app/main/forms.py b/app/main/forms.py
index 957e7c11a..985f50bc6 100644
--- a/app/main/forms.py
+++ b/app/main/forms.py
@@ -100,7 +100,7 @@ def get_next_hours_until(until):
     now = datetime.utcnow()
     hours = int((until - now).total_seconds() / (60 * 60))
     return [
-        (now + timedelta(hours=i)).replace(minute=0, second=0).replace(tzinfo=pytz.utc)
+        (now + timedelta(hours=i)).replace(minute=0, second=0, microsecond=0).replace(tzinfo=pytz.utc)
         for i in range(1, hours + 1)
     ]
 
@@ -979,6 +979,24 @@ class ChooseTimeForm(StripWhitespaceForm):
     )
 
 
+class ChooseBroadcastDurationForm(StripWhitespaceForm):
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.finishes_at.choices = [
+            get_time_value_and_label(hour) for hour in get_next_hours_until(
+                get_furthest_possible_scheduled_time()
+            )
+        ]
+        self.finishes_at.categories = get_next_days_until(
+            get_furthest_possible_scheduled_time()
+        )
+
+    finishes_at = RadioField(
+        'When should this broadcast end?',
+    )
+
+
 class CreateKeyForm(StripWhitespaceForm):
     def __init__(self, existing_keys, *args, **kwargs):
         self.existing_key_names = [
diff --git a/app/main/views/broadcast.py b/app/main/views/broadcast.py
index 7dda048e8..be2f07ecc 100644
--- a/app/main/views/broadcast.py
+++ b/app/main/views/broadcast.py
@@ -1,8 +1,12 @@
-from flask import abort, jsonify, redirect, render_template, request, url_for
+from flask import abort, jsonify, redirect, render_template, url_for
 
 from app import current_service
 from app.main import main
-from app.main.forms import BroadcastAreaForm, SearchByNameForm
+from app.main.forms import (
+    BroadcastAreaForm,
+    ChooseBroadcastDurationForm,
+    SearchByNameForm,
+)
 from app.models.broadcast_message import BroadcastMessage, BroadcastMessages
 from app.utils import service_has_permission, user_has_permissions
 
@@ -141,15 +145,19 @@ def preview_broadcast_message(service_id, broadcast_message_id):
         broadcast_message_id,
         service_id=current_service.id,
     )
-    if request.method == 'POST':
-        broadcast_message.request_approval()
+    form = ChooseBroadcastDurationForm()
+
+    if form.validate_on_submit():
+        broadcast_message.request_approval(until=form.finishes_at.data)
         return redirect(url_for(
             '.broadcast_dashboard',
             service_id=current_service.id,
         ))
+
     return render_template(
         'views/broadcast/preview-message.html',
         broadcast_message=broadcast_message,
+        form=form,
     )
 
 
diff --git a/app/models/broadcast_message.py b/app/models/broadcast_message.py
index 8e7deb224..6703401c1 100644
--- a/app/models/broadcast_message.py
+++ b/app/models/broadcast_message.py
@@ -1,4 +1,4 @@
-from datetime import datetime, timedelta
+from datetime import datetime
 
 from notifications_utils.broadcast_areas import broadcast_area_libraries
 from notifications_utils.template import BroadcastPreviewTemplate
@@ -33,7 +33,6 @@ class BroadcastMessage(JSONModel):
         'approved_by_id',
         'cancelled_by_id',
     }
-    DEFAULT_TTL = timedelta(hours=72)
 
     libraries = broadcast_area_libraries
 
@@ -132,9 +131,9 @@ class BroadcastMessage(JSONModel):
             data=kwargs,
         )
 
-    def request_approval(self):
+    def request_approval(self, until):
         self._update(
-            finishes_at=(datetime.utcnow() + self.DEFAULT_TTL).isoformat(),
+            finishes_at=until,
         )
         self._set_status_to('pending-approval')
 
diff --git a/app/templates/components/radios.html b/app/templates/components/radios.html
index e41e57af4..eb55217b0 100644
--- a/app/templates/components/radios.html
+++ b/app/templates/components/radios.html
@@ -23,7 +23,8 @@
 {% macro radio_select(
  field,
  hint=None,
- wrapping_class='form-group'
+ wrapping_class='form-group',
+ show_now_as_default=True
 ) %}
  <div class="{{ wrapping_class }} {% if field.errors %} form-group-error{% endif %}">
    <fieldset>
@@ -35,7 +36,7 @@
          </span>
        {% endif %}
      </legend>
-     <div class="radio-select" data-module="radio-select" data-categories="{{ field.categories|join(',') }}">
+     <div class="radio-select" data-module="radio-select" data-categories="{{ field.categories|join(',') }}" data-show-now-as-default="{{ show_now_as_default }}">
        <div class="radio-select-column">
        {% for option in field %}
          <div class="multiple-choice">
diff --git a/app/templates/views/broadcast/preview-message.html b/app/templates/views/broadcast/preview-message.html
index bed3cae07..8fa7a771c 100644
--- a/app/templates/views/broadcast/preview-message.html
+++ b/app/templates/views/broadcast/preview-message.html
@@ -1,7 +1,8 @@
 {% from "components/button/macro.njk" import govukButton %}
 {% from "components/form.html" import form_wrapper %}
 {% from "components/page-header.html" import page_header %}
-{% from "components/page-footer.html" import sticky_page_footer %}
+{% from "components/page-footer.html" import page_footer %}
+{% from "components/radios.html" import radio_select %}
 
 {% extends "withnav_template.html" %}
 
@@ -28,7 +29,11 @@
   {{ broadcast_message.template|string }}
 
   {% call form_wrapper() %}
-    {{ sticky_page_footer('Submit for approval') }}
+    {{ radio_select(
+      form.finishes_at,
+      show_now_as_default=False
+    ) }}
+    {{ page_footer('Submit for approval') }}
   {% endcall %}
 
 {% endblock %}
diff --git a/tests/app/main/test_choose_time_form.py b/tests/app/main/test_choose_time_form.py
index a0f2618c4..41b32f90a 100644
--- a/tests/app/main/test_choose_time_form.py
+++ b/tests/app/main/test_choose_time_form.py
@@ -11,19 +11,19 @@ def test_form_contains_next_24h(app_):
 
     # Friday
     assert choices[0] == ('', 'Now')
-    assert choices[1] == ('2016-01-01T12:00:00.061258', 'Today at midday')
-    assert choices[13] == ('2016-01-02T00:00:00.061258', 'Today at midnight')
+    assert choices[1] == ('2016-01-01T12:00:00', 'Today at midday')
+    assert choices[13] == ('2016-01-02T00:00:00', 'Today at midnight')
 
     # Saturday
-    assert choices[14] == ('2016-01-02T01:00:00.061258', 'Tomorrow at 1am')
-    assert choices[37] == ('2016-01-03T00:00:00.061258', 'Tomorrow at midnight')
+    assert choices[14] == ('2016-01-02T01:00:00', 'Tomorrow at 1am')
+    assert choices[37] == ('2016-01-03T00:00:00', 'Tomorrow at midnight')
 
     # Sunday
-    assert choices[38] == ('2016-01-03T01:00:00.061258', 'Sunday at 1am')
+    assert choices[38] == ('2016-01-03T01:00:00', 'Sunday at 1am')
 
     # Monday
-    assert choices[84] == ('2016-01-04T23:00:00.061258', 'Monday at 11pm')
-    assert choices[85] == ('2016-01-05T00:00:00.061258', 'Monday at midnight')
+    assert choices[84] == ('2016-01-04T23:00:00', 'Monday at 11pm')
+    assert choices[85] == ('2016-01-05T00:00:00', 'Monday at midnight')
 
     with pytest.raises(IndexError):
         assert choices[
diff --git a/tests/app/main/views/test_broadcast.py b/tests/app/main/views/test_broadcast.py
index edad43dd8..e9b2a761d 100644
--- a/tests/app/main/views/test_broadcast.py
+++ b/tests/app/main/views/test_broadcast.py
@@ -278,22 +278,79 @@ def test_remove_broadcast_area_page(
     )
 
 
+@pytest.mark.parametrize('end_time', (
+
+    # Before now
+    pytest.param('2020-02-02T02:00:00', marks=pytest.mark.xfail),
+
+    # End of the current hour
+    pytest.param('2020-02-02T03:00:00'),
+
+    # Midnight 3 days ahead
+    pytest.param('2020-02-06T00:00:00'),
+
+    # 1am 4 days ahead
+    pytest.param('2020-02-06T01:00:00', marks=pytest.mark.xfail),
+
+))
+@freeze_time('2020-02-02 02:02:02')
 def test_preview_broadcast_message_page(
     client_request,
     service_one,
     mock_get_draft_broadcast_message,
     mock_get_broadcast_template,
     fake_uuid,
+    end_time,
 ):
     service_one['permissions'] += ['broadcast']
-    client_request.get(
+
+    page = client_request.get(
         '.preview_broadcast_message',
         service_id=SERVICE_ONE_ID,
         broadcast_message_id=fake_uuid,
-    ),
+    )
+
+    assert [
+        normalize_spaces(area.text)
+        for area in page.select('.area-list-item.area-list-item--unremoveable')
+    ] == [
+        'England',
+        'Scotland',
+    ]
+
+    assert normalize_spaces(
+        page.select_one('.broadcast-message-wrapper').text
+    ) == (
+        'This is a test'
+    )
+
+    form = page.select_one('form')
+    assert form['method'] == 'post'
+    assert 'action' not in form
+
+    radio_choices = [
+        choice['value'] for choice in form.select('input[type=radio][name=finishes_at]')
+    ]
+    assert len(radio_choices) == 94
+    assert end_time in radio_choices
 
 
-@freeze_time('2020-02-02 02:02:02.222222')
+@pytest.mark.parametrize('end_time', (
+
+    # Before now
+    pytest.param('2020-02-02T02:00:00', marks=pytest.mark.xfail),
+
+    # End of the current hour
+    pytest.param('2020-02-02T03:00:00'),
+
+    # Midnight 3 days ahead
+    pytest.param('2020-02-06T00:00:00'),
+
+    # 1am 4 days ahead
+    pytest.param('2020-02-06T01:00:00', marks=pytest.mark.xfail),
+
+))
+@freeze_time('2020-02-02 02:02:02')
 def test_start_broadcasting(
     client_request,
     service_one,
@@ -302,24 +359,54 @@ def test_start_broadcasting(
     mock_update_broadcast_message,
     mock_update_broadcast_message_status,
     fake_uuid,
+    end_time,
+):
+    service_one['permissions'] += ['broadcast']
+    client_request.post(
+        '.preview_broadcast_message',
+        service_id=SERVICE_ONE_ID,
+        broadcast_message_id=fake_uuid,
+        _data={
+            'finishes_at': end_time,
+        }
+    ),
+    mock_update_broadcast_message.assert_called_once_with(
+        service_id=SERVICE_ONE_ID,
+        broadcast_message_id=fake_uuid,
+        data={
+            'finishes_at': end_time,
+        },
+    )
+    mock_update_broadcast_message_status.assert_called_once_with(
+        'pending-approval',
+        service_id=SERVICE_ONE_ID,
+        broadcast_message_id=fake_uuid,
+    )
+
+
+def test_start_broadcasting_shows_validation_error(
+    client_request,
+    service_one,
+    mock_get_draft_broadcast_message,
+    mock_get_broadcast_template,
+    mock_update_broadcast_message,
+    mock_update_broadcast_message_status,
+    fake_uuid,
 ):
     service_one['permissions'] += ['broadcast']
-    client_request.post(
+    page = client_request.post(
         '.preview_broadcast_message',
         service_id=SERVICE_ONE_ID,
         broadcast_message_id=fake_uuid,
-    ),
-    mock_update_broadcast_message.assert_called_once_with(
-        service_id=SERVICE_ONE_ID,
-        broadcast_message_id=fake_uuid,
-        data={
-            'finishes_at': '2020-02-05T02:02:02.222222',
-        },
+        _data={},
+        _expected_status=200,
     )
-    mock_update_broadcast_message_status.assert_called_once_with(
-        'pending-approval',
-        service_id=SERVICE_ONE_ID,
-        broadcast_message_id=fake_uuid,
+    assert mock_update_broadcast_message.called is False
+    assert mock_update_broadcast_message_status.called is False
+    assert normalize_spaces(
+        page.select_one('form fieldset legend .error-message').text
+    ) == (
+        'Select an option'
     )
 
 
diff --git a/tests/javascripts/radioSelect.test.js b/tests/javascripts/radioSelect.test.js
index 31b8dba85..c41481208 100644
--- a/tests/javascripts/radioSelect.test.js
+++ b/tests/javascripts/radioSelect.test.js
@@ -99,7 +99,7 @@ describe('RadioSelect', () => {
         <legend class="form-label">
           When should Notify send these messages?
         </legend>
-        <div class="radio-select" data-module="radio-select" data-categories="${CATEGORIES.join(',')}">
+        <div class="radio-select" data-module="radio-select" data-categories="${CATEGORIES.join(',')}" data-show-now-as-default="True">
           <div class="radio-select__column">
             <div class="multiple-choice">
               <input checked="" id="scheduled_for-0" name="scheduled_for" type="radio" value="">