<b-datepicker disabled v-model="endDate" placeholder="Select Date" icon="calendar-today"> </b-datepicker>
moment(new Date()).add(7, 'days').toDate()
You should be careful, Date() and new Date() are different things when you use Date object. If you use Date() directly, this will be a string. If you use with new keyword this will be an object. So, in this case, I'll use like that;
this.endDate = moment(new Date()).add(7, 'days').toDate()
I hope this will help you.