DateRange Issues

I'm having some trouble getting the dateRange to work on an events page. I have the date's set for all of my child pages, but when I add the dateRange start to today nothing is showing up. I've even tried setting the date to an actual date with no luck. Here is what my main event's page collection looks like:

content:
    items: '@self.children'
    limit: 6
    order:
        dir: asc
        by: date
    dateRange:
        start: today
    pagination: true
    url_taxonomy_filters: false

And here is a sample of an events data:

title: 'Bingo + Ice Cream Social'
date: '28-04-2016 18:00'

and another that wouldn't be expired:

title: BBQ
date: '30-07-2016 12:00'

Any help is appreciated. I'm sure it is something small that I'm just missing.

dateRange takes two dates, a start and an end. Also these dates must be in a format that strtotime() understands, so today will not work.

More info in the docs.

Thank you! Adding in an end parameter worked perfectly. In the docs it says both start and end are optional. Is that incorrect then?

Sounds like the docs might need an update!