tooltip_date_format

specifies the format of start and end dates displayed in the tooltip

date

Date

the date which needs formatting

Example

gantt.templates.tooltip_date_format=function (date){
    var formatFunc = gantt.date.date_to_str("%Y-%m-%d %H:%i");
    return formatFunc(date);
};

Details

This template is defined in the tooltip extension, so you need to activate the tooltip plugin. Read the details in the Tooltips for Gantt Elements article.