Without parameters:

{countdown}

With time:

{countdown time=100}

With data:

{countdown date=25/12/2017 12:45:30}

{countdown date=25/12/2017 12:45}

{countdown date=25/12/2017}

{countdown date=25/12 12:45:30}

{countdown date=25/12 12:45}

{countdown date=25/12}

With style:

{countdown time=100 style=flip}

{countdown time=200 style=orange}

{countdown time=300 style=blue}

{countdown time=300 style=joomlafestival}

With width:

{countdown time=150 width=500}

{countdown time=250 width=300}