How to get the current date time in Java

Question

What's the best way to get the current date/time in Java?

Answer 1

It depends on what form of date/time you want:

• If you want the date/time as a single numeric value, then System.currentTimeMillis() gives you that, expressed as the number of milliseconds after the UNIX epoch (as a Java long). This value is a delta from a UTC time-point and is independent of the local time-zone ... assuming that the system clock has been set correctly.

• If you want the date/time in a form that allows you to access the components (year, month, etc) numerically, you could use one of the following:

  • new Date() gives you a Date object initialized with the current date/time. The problem is that the Date API methods are mostly flawed ... and deprecated.

  • Calendar.getInstance() gives you a Calendar object initialized with the current date/time, using the default Locale and TimeZone. Other overloads allow you to use a specific Locale and/or TimeZone. The calendar works ... but the APIs are still cumbersome.

  • new org.joda.time.DateTime() gives you a Joda-time object initialized with the current date/time, using the default time zone and chronology. There are lots of other Joda alternatives ... too many to describe here. (But note that some people report that Joda time has performance issues.; e.g. Jodatime's LocalDateTime is slow when used the first time.)

  • in Java 8, calling java.time.LocalDateTime.now() and java.time.ZonedDateTime.now() will give you representations¹ for the current date / time.