How to change the date format for the receipt date in a template
If you want 28 February 2019
{foreach from=$contributions item=contribution} {assign
    var="date" value=$contribution.receive_date|date_format:"%d %B %Y"}

If you want 28 02 2019
{foreach from=$contributions item=contribution} {assign
    var="date" value=$contribution.receive_date|date_format:"%d %m %Y"}

If you want it to look better (28/02/2019) you can add slashes value=$contribution.receive_date|date_format:"%d/%m/%Y"}