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Date picker 0:49
A 49-second explainer of Date picker, narrated over the same demo you can try yourself.
Try the interactive Date picker demo
What this video covers
A date picker lets you choose a date from a calendar rather than typing it into a text box. Its job is to remove ambiguity and error: it shows valid days, settles the format question for you, and makes "03/04" impossible to misread - because you pick the day rather than describe it.
Typed, "03/04" could have meant March or April, and nothing stopped a date that doesn't exist. Picked from the calendar, there was no format to get wrong and no invalid day to choose - the constraint did the error-checking for you. The picker didn't add a step so much as remove a class of mistakes.