events_group = [{
        'date': now.date(),
        'today': True,
        'events': []
    }]
 
    for event in events:
        event_date = event.date_start.date()
        if event_date <= now.date():
            events_group[0]['events'].append(event)
        else:
            if event_date != events_group[-1]['date']:
                events_group.append({
                    'date': event_date,
                    'events': []
                })
 
            events_group[-1]['events'].append(event)
 
    if len(events_group[0]['events']) == 0:
        events_group.pop(0)

import itertools
 
now_date = now.date()
events_group = []
for date, events in itertools.groupby(events, key=lambda x: x.date_start.date()):
    events_group.append({'date': date, 
                         'events': list(events),
                         'today': date == now_date})

    for date, events in itertools.groupby(events, key=lambda x: x.date_start.date()):
        events_group.append({
            'date': date,
            'events': list(events),
            'after_days': abs((now.date() - date).days)
        })

            {% if group.after_days == 0 %}
            Сегодня /
            {% elif group.after_days == 1 %}
            Завтра /
            {% elif group.after_days == 2 %}
            Послезавтра /
            {% endif %}