You can use the DayJS library for date manipulation in calculators: DayJS Documentation
The DayJS library is created by calling the dayjs method of utils:
let newDate=utils.dayjs('2021-02-17');
This would create a new date from the specified string.
Formatting
You can format a date to a string:
let newDate=utils.dayjs('2021-02-17').format('MM-DD-YYYY');
Timezones
You can specify a timezone to create the date with:
let newDate=utils.dayjs('2021-02-17','America/New_York');
Specifying utc will force the date to be recorded as utc:
let newDate=utils.dayjs('2021-02-17','utc');
You can also convert dates between different timezones:
let newDate=utils.dayjs('2021-02-17','utc').tz('America/New_York');