Ionic 2 JSON dates and moment.js trouble

Question

I have a problem with dates manipulation with Ionic and moment.js. I store some dates from a ion-datetime component :

{"year":2017,"month":7,"day":26,"hour":null,"minute":null,"second":null,"millisecond":null,"tzOffset":0}

And use moment.js to "humanize" date display :

let somedate = moment(some.date);
console.log('JSON date : ' + JSON.stringify(some.date) + ' resolved as : ' + somedate.format('DD/MM/YYYY'));

And got result :

Original JSON date : {"year":2017,"month":7,"day":26,"hour":null,"minute":null,"second":null,"millisecond":null,"tzOffset":0} resolved as : 26/08/2017

As you can consider, there's on month offset between original JSON date and moment display date...

What i'm missing ?

Answer 1

The Javascript month are in range of 0-11 ie January is 0, February is 1 and likewise, therefore it is moving you to the next month. Try subtracting 1 from month value, to get the correct month.

 var some = {'date':{"year":2017,"month":6,"day":26,"hour":null,"minute":null,"second":null,"millisecond":null,"tzOffset":0} }; let somedate = moment(some.date); console.log('JSON date : ' + JSON.stringify(some.date) + ' resolved as : ' + somedate.format('DD/MM/YYYY')); 

 <script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.18.1/moment.min.js"></script> 

Answer 2

Finally, with your answers, i resolved the problem with a conversion method that take the original JSON date format and return a Javascript Date object, using TypeScript :

  private _JSONDateToDate(jsonDate: any){
if(typeof jsonDate == 'object')
  return new Date(jsonDate.year, (parseInt(jsonDate.month) - 1), jsonDate.day);

return jsonDate;

}

I substract 1 month of the "month" property in order to have a correct Date object... then, i can manipulate it with moment.js