items = [{
date: new Date(2018, 1, 2),
event: 'test1'
},
{
date: new Date(2018, 1, 2),
event: 'test2'
},
{
date: new Date(2018, 1, 3),
event: 'test3'
},
{
date: new Date(2018, 1, 4),
event: 'test4'
},
{
date: new Date(2018, 1, 4),
event: 'test5'
},
{
date: new Date(2018, 1, 4),
event: 'test6'
},
{
date: new Date(2018, 1, 5),
event: 'test7'
},
];
<div *ngFor="let item of items; let i = index">
<span *ngIf="(i>0) && ((items[i-1].date | date:'dd/mm/yyyy') !== (items[i].date | date:'dd/mm/yyyy'))">
{{i}} {{item.event}} {{ items[i].date}} {{ items[i-1].date}}
</span>
</div>