Groovy - Compare date and Time - shell

Question

I have two strings , which are each got from respective shell commands and are not uniformly formatted.
Two strings obtained are as follows:
Date : Tue Feb 28 16:23:20 2017 -0600
Executed at : Tue Feb 28 17:24:06 EST 2017
EDIT: I get the above mentioned dates , one through git log and other through cat and store both in variables
First date is got through and stored in X:
sh 'git log <file> | grep Date | head -n 1 > X '
Second date is got through below and stored in Y:
sh 'cat chef-policy-release.log | grep <file> | tail -n 1 | grep -o "Executed at.*" > Y'
Now I wanted to pick out just date and time among that and wanted to check if executed time is after the Date value or not ?

Answer 1

Similar to Rao's answer, but with a function to parse the string, no need for date format strings, and without creating un-needed Date instances:
class DateTest{
public static void main(String[] args) {
String logDateString = args[0];
String execDateString = args[1];
Date logDate = parseDate(logDateString);
Date execDate = parseDate(execDateString);
System.out.println(execDate > logDate);
}
static def parseDate(String rawString) {
String dateString = rawString.substring(rawString.indexOf(":") + 1).trim();
new Date(Date.parse(dateString));
}
}

Answer 2

Here you go.
def dateStr1 = 'Tue Feb 28 16:23:20 2017 -0600'
def dateStr2 = 'Tue Feb 28 17:24:06 EST 2017'
def pattern1 = "EEE MMM dd HH:mm:ss yyyy Z"
def pattern2 = "EEE MMM dd HH:mm:ss z yyyy"
def date = new Date().parse(pattern1, dateStr1)
def executeDate = new Date().parse(pattern2, dateStr2)
assert date < executeDate, 'Execute Date is earlier than the date'
You may quickly try it online (negative test)Demo
EDIT: Based on OP's comment to parse the string and extract the date
You could have applied #GreBeardedGeek's parsing logic.
//Closure to get the date parsed
def getDate = { delimiter, dateFormat, dateStr ->
def dt = dateStr.substring(dateStr.indexOf(delimiter) + 1).trim()
println dt
new Date().parse(dateFormat, dt)
}
def dateStr1 = 'Date : Tue Feb 28 16:23:20 2017 -0600'
def dateStr2 = 'Executed at : Tue Feb 28 17:24:06 EST 2017'
def pattern1 = "EEE MMM dd HH:mm:ss yyyy Z"
def pattern2 = "EEE MMM dd HH:mm:ss z yyyy"
def date = getDate(':', pattern1, dateStr1)
def executeDate = getDate(':', pattern2, dateStr2)
assert date < executeDate, 'Execute Date is earlier than the date'
Edit#2​ can be more simplified to:
//Set / assign the two dates
def dateStr1 = 'Date : Tue Feb 28 16:23:20 2017 -0600'
def dateStr2 = 'Executed at : Tue Feb 28 17:24:06 EST 2017'
def getDate = { dateStr -> Date.parse(dateStr.substring(dateStr.indexOf(':') + 1).trim()) }
assert getDate(dateStr1) < getDate(dateStr2), 'Execute Date is earlier than the date'