TypeScript bindings: abstract literal union types into separate types?

[aartaka]

So I'm working on translating some string fields from CCDA to FHIR. FHIR type definitions have a form of:

export interface PractitionerRoleAvailableTime extends BackboneElement {
    allDay?: boolean;
    availableEndTime?: string;
    availableStartTime?: string;
    daysOfWeek?: 'mon' | 'tue' | 'wed' | 'thu' | 'fri' | 'sat' | 'sun'[];
}

where daysOfWeek, for instance, is a union of literals type. There may be more than ten literals in this field's type. While I'm providing a meager string when setting this field. So TypeScript (justifiably) complains that string is not compatible with 'mon' | 'tue' | 'wed' | 'thu' | 'fri' | 'sat' | 'sun'.

I don't want to provide a full 'mon' | 'tue' | 'wed' | 'thu' | 'fri' | 'sat' | 'sun' as a type for every string I use for this field. Especially given how many literals there might be. Having an abstracted type (DayOfWeek) would be perfect for that.

But I realize that it might be hard to implement. Parsing ValueSets, I guess?