[GROOVY-7964] TimeCategory incorrectly counts days difference between two dates

• Type: Bug
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 2.4.7
• Component/s: groovy-runtime
• Labels: timecategory
• Environment: Windows 10 x86_64, Oracle Java 1.8.0.102 x86_64
• Assignee: Unassigned
• Reporter: Los Pejos
• Created: 10/Oct/16 12:39
• Updated: 24/Mar/17 06:58

Description

TimeCategory incorrectly counts days difference between two dates.
Exhibit (Groovy code):

#!/usr/bin/env groovy

@Grab(group='joda-time', module='joda-time', version='2.9.4+')

import java.io.BufferedReader
import java.io.IOException
import java.io.InputStreamReader
import java.time.LocalDate
import java.time.format.DateTimeFormatter
import java.time.temporal.ChronoUnit

import groovy.time.TimeCategory

String date1 = '2016-03-22'
String date2 = '2016-03-29'
String fmt = 'yyyy-MM-dd'


// Java 8 ChronoUnit:

DateTimeFormatter formatter = DateTimeFormatter.ofPattern(fmt)

//LocalDate firstDate = LocalDate.parse(date1, formatter)
//LocalDate secondDate = LocalDate.parse(date2, formatter)
long days = ChronoUnit.DAYS.between(
	LocalDate.parse(date1, formatter), 
	LocalDate.parse(date2, formatter)
)

println "Java 8 ChronoUnit: Dates between $date1 and $date2 : $days"

// Groovy TimeCategory/Date:
use (TimeCategory) {
	def d = (Date.parse(fmt, date2) - Date.parse(fmt, date1)).days
	println "Groovy TimeCategory/Date: Dates between $date1 and $date2 : $d"
}


// Joda Time:
// LocalDate fromDateFields(Date date)
// Date.parse('yyyy-MM-dd', [e-mail]())

days = org.joda.time.Days.daysBetween(
	org.joda.time.LocalDate.fromDateFields(Date.parse(fmt,date1)), 
	org.joda.time.LocalDate.fromDateFields(Date.parse(fmt,date2))
).getDays()
println "Joda Time: Dates between $date1 and $date2 : $days"

Current Output:

$ groovy DatesDiff.groovy
Java 8 ChronoUnit: Dates between 2016-03-22 and 2016-03-29 : 7
Groovy TimeCategory/Date: Dates between 2016-03-22 and 2016-03-29 : 6
Joda Time: Dates between 2016-03-22 and 2016-03-29 : 7

Expected Output:

$ groovy DatesDiff.groovy
Java 8 ChronoUnit: Dates between 2016-03-22 and 2016-03-29 : 7
Groovy TimeCategory/Date: Dates between 2016-03-22 and 2016-03-29 : 7
Joda Time: Dates between 2016-03-22 and 2016-03-29 : 7

Resume: notice the difference in "Groovy TimeCategory/Date" line.