Date and Time

package: java.time
LocalDate — for date only: years, months, days
LocalTime — for time only: hour, minutes, seconds, nanoseconds
LocalDateTime — LocalDate + LocalTime: No Timezone info
Instant
- represent an instantaneous moment on the timeline
- internally long variable to store seconds counting from epoch
- internally int variable to store nanosecond
- useful for generating a time stamp to represent machine time
- Doesn’t include Timezone and hence is always at GMT0
Period — date based
- Period.between(startLocalDate, endLocalDate)
- Don’t have timezone info
Duration — time based
- Duration.between(startLocalTime, endLocalTime)
- Don’t have timezone info
With Timezone info
- OffsetDateTime — LocalDateTime + ZoneOffset
- OffsetTime — LocalTime + ZoneOffset
- ZonedDateTime
  - OffsetDateTime + ZoneRules
  - account for daylight savings and any other anomalies
legacy
- java.util.Date
- java.util.Calendar
- java.util.TimeZone

Epoch