LocalAndZonedDates

LocalAndZonedDates.groovy

import java.time.LocalDate
import java.time.ZonedDateTime
import java.time.ZoneId
import java.time.format.DateTimeFormatter
import java.time.temporal.TemporalAdjusters

// If you have a date without time information, use a LocalDate.  e.g. someone's birthday
LocalDate localDate = new LocalDate(2016, 4, 12)
println localDate.toString()  // 2016-04-12

//
// If you need to include time in the date, use ZonedDateTime
//
ZonedDateTime zdt = ZonedDateTime.now() 

// when formatting a ZonedDateTime for API communication, you'll typically want to use format(DateTimeFormatter.ISO_INSTANT)
println zdt.format(DateTimeFormatter.ISO_INSTANT)          // 2016-04-12T19:20:45.539Z

// examples of other formatters included out of the box in the DateTimeFormatter
println zdt.format(DateTimeFormatter.ISO_LOCAL_DATE_TIME)  // 2016-04-12T14:20:45.539
println zdt.format(DateTimeFormatter.RFC_1123_DATE_TIME)   // Tue, 12 Apr 2016 14:20:45 -0500
println zdt.format(DateTimeFormatter.ISO_ZONED_DATE_TIME)  // 2016-04-12T14:20:45.539-05:00[America/Chicago]

// you can also create a custom formatter
DateTimeFormatter hammerTimeFormatter = DateTimeFormatter.ofPattern("MMM dd yyyy GG")
println zdt.format(hammerTimeFormatter)                    // Apr 12 2016 AD