Clone moment js object
There's a method to clone a moment object:
const yearBefore = this.state.startDate.clone().subtract(1, 'years');
It would also be a better idea to store a serialisable representation of the date in your component state, such as the result of calling .valueOf()
on either a Date or a Moment, either of which returns the number of milliseconds since the UNIX epoch.
It's also possible to copy a moment
object through it's constructor. Like so
const firstMoment = moment("2020-08-18");
const clone = moment(firstMoment);
moment.js has its own api for cloning moment object.
var copy = momentObj.clone();
And I agree on storing dates serialize representation instead of Object in store.