DRAFT--do not review
You can use the date and time functions to perform various operations on dates and times in the Wrangler. Functions that specify dates, times, or timestamps in the arguments use strings with specific formats:
For a date, the format is %yyyy-%mm-%dd and is of java type LocalDate.
For a time, the format is %hh:%nn:%ss. If extended to include microseconds, the format is %hh:%nn:%ss.x where x gives the number of decimal places seconds is given to. time is of type LocalTime.
For a timestamp, the format is the date format followed by the time format. timestamp is of type LocalDateTime.
Functions that have the days of week in the argument take a string that specifies the day of the week. The day is specified as a three-letter abbreviation, or the full name. For example, the strings "mon" and "monday" are both valid.