Tabs abstract view not working

ionic-v1
1

Hello,

I am trying to implement tabs. I want it to look something like this:
image

Code follows…

.state('app.schedule', {
    url: '/schedule',
    abstract: true,
    templateUrl: 'templates/schedule.html'
})

.state('app.schedule.day1', {
    url: '/day1',
    views: {
        'day1': {
            templateUrl: 'templates/day1.html',
            controller: 'ScheduleCtrl'
        }
    }
})

.state('app.schedule.day2', {
    url: '/day2',
    views: {
        'day2': {
            templateUrl: 'templates/day2.html',
            controller: 'ScheduleCtrl'
        }
    }
})

.state('app.schedule.day3', {
    url: '/day3',
    views: {
        'day3': {
            templateUrl: 'templates/day3.html',
            controller: 'ScheduleCtrl'
        }
    }
})

.state('app.schedule.day4', {
    url: '/day4',
    views: {
        'day4': {
            templateUrl: 'templates/day4.html',
            controller: 'ScheduleCtrl'
        }
    }
})

<ion-view view-title="Schedule">
<ion-tabs class="tabs-icon-top tabs-stable tabs-striped tabs-top tabs-positive">
    <ion-tab title="Oct-1" icon="ion-android-calendar" ui-sref="app.schedule.day1">
        <ion-nav-view name="day1"></ion-nav-view>
    </ion-tab>
    <ion-tab title="Oct-2" icon="ion-android-calendar" ui-sref="app.schedule.day2">
        <ion-nav-view name="day2"></ion-nav-view>
    </ion-tab>
    <ion-tab title="Oct-3" icon="ion-android-calendar" ui-sref="app.schedule.day3">
        <ion-nav-view name="day3"></ion-nav-view>
    </ion-tab>
    <ion-tab title="Oct-4" icon="ion-android-calendar" ui-sref="app.schedule.day4">
        <ion-nav-view name="day4"></ion-nav-view>
    </ion-tab>
</ion-tabs>

However when I click on schedule link, nothing happens.
But it works when I change the route of schedule page as below:

.state('app.schedule', {
    url: '/schedule',
    views: {
        'menuContent': {
            templateUrl: 'templates/schedule.html'
        }
    }
})

A tab parent view should be abstract right? Why is it not working in my case? Am I missing something?