Fixed month reference in documented output of parseDate and parseDateTime function calls (#3859)

std/datetime/README.md

@@ -14,12 +14,12 @@ Simple helper to help parse date strings into `Date`, with additional functions.
 ```ts
 import { parseDate, parseDateTime } from 'https://deno.land/std/datetime/mod.ts'
 
-parseDate("03-01-2019", "dd-mm-yyyy") // output : new Date(2019, 1, 3)
-parseDate("2019-01-03", "yyyy-mm-dd") // output : new Date(2019, 1, 3)
+parseDate("20-01-2019", "dd-mm-yyyy") // output : new Date(2019, 0, 20)
+parseDate("2019-01-20", "yyyy-mm-dd") // output : new Date(2019, 0, 20)
 ...
 
-parseDateTime("01-03-2019 16:34", "mm-dd-yyyy hh:mm") // output : new Date(2019, 1, 3, 16, 34)
-parseDateTime("16:34 01-03-2019", "hh:mm mm-dd-yyyy") // output : new Date(2019, 1, 3, 16, 34)
+parseDateTime("01-20-2019 16:34", "mm-dd-yyyy hh:mm") // output : new Date(2019, 0, 20, 16, 34)
+parseDateTime("16:34 01-20-2019", "hh:mm mm-dd-yyyy") // output : new Date(2019, 0, 20, 16, 34)
 ...
 ```