Angularjs: change object property of specific index of nested ng-repeat

I’ve nested ng-repeat like this:

<div ng-repeat="(dayOfWeek, time) in uiHoursOfOperation track by $index" ng-init="daysOfWeekIndex=$index">

 <div class="" ng-repeat="openCloseSet in time.uiDayMs track by $index">
    <md-input-container>
      <md-select ng-model="openCloseSet[0]" ng-init="openTime = openCloseSet[0]">
        <md-option ng-repeat="uiTime in time.avaiableTime" ng-value="uiTime.msValue">
        {{::uiTime.display}}
        </md-option>
      </md-select>
     </md-input-container>

    <md-input-container ng-if="$index === 0">
      <md-button ng-click="addSplitHours(time.uiDayMs ,$index +1, time)">
         Add                                      
      </md-button>
    </md-input-container>
 </div>

</div>

On clicking the Add button. It creates a new block of time.uiDayMs.

Here is the add function:

$scope.addSplitHours = addSplitHours;
function addSplitHours(index, time) {
    var newOpen = time.uiDayMs[time.uiDayMs.length - 1][1] + 900000;
    time.uiDayMs.push([newOpen, newOpen + 900000 * 4]);

    var closingtimeStarts = closingTime + 900000;
    var closingtimeEnds = avaiableClosingTimes[avaiableClosingTimes.length - 1].msValue;
    for (
        var msValue = closingtimeStarts;
        msValue <= closingtimeEnds;
        msValue += 900000
    ) {
        time.avaiableTime.push({
            msValue: msValue,
            display: moment(msValue)
                .utc()
                .format("h:mm A")
        });
    }
}

You can see I’m taking the next index number but unable to use it.
So my main question is how can I make the time.avaiableTime.push to only that specific index? Currently, It changes on each time.avaiableTime but I wanted to push on that specific index only.

Source: AngularJS