MAT_DATE_FORMATS definition/meaning of fields

Question

Material example for customizing-the-parse-and-display-formats for date picker uses custom MAT_DATE_FORMATS

export const MY_FORMATS = {   parse: {     dateInput: 'LL',   },   display: {     dateInput: 'LL',     monthYearLabel: 'MMM YYYY',     dateA11yLabel: 'LL',     monthYearA11yLabel: 'MMMM YYYY',   }, }; 

I could not find where and how these fields like dateA11yLabel will come into play. What I could figure out was display.dateInput is used in displaying selected date on calendar and display.monthYearLabel is used in the select drop-down of year selector.

1. Where are rest of the fields used?
2. When writing custom MAT_DATE_FORMATS is it mandatory to define all fields?

Answer 1

Well, I figured out the following:

 parse: {      dateInput: 'DD.MM.YYYY',   },    display: {      dateInput: 'DD.MM.YYYY',     monthYearLabel: 'MMM YYYY',     dateA11yLabel: 'LL',     monthYearA11yLabel: 'MMMM-YYYY',   }, 

• with parse.dateInput: you can let the user enter any type of date with any format, and the date adapter will reformat it to the format you specify in this attribute

• with display.dateInput you can specify the input date format (marked with 1)

• display.monthYearLabel you can specify the area marked with 2

unfortunately, I still don't know about the rest!