boolean isWithinRange(Date testDate) {
   return !(testDate.before(startDate) || testDate.after(endDate));
}

Doesn't seem that awkward to me. Note that I wrote it that way instead of

return testDate.after(startDate) && testDate.before(endDate);

so it would work even if testDate was exactly equal to one of the end cases.

That's the correct way. Calendars work the same way. The best I could offer you (based on your example) is this:

boolean isWithinRange(Date testDate) {
    return testDate.getTime() >= startDate.getTime() &&
             testDate.getTime() <= endDate.getTime();
}

Date.getTime() returns the number of milliseconds since 1/1/1970 00:00:00 GMT, and is a long so it's easily comparable.

Consider using Joda Time. I love this library and wish it would replace the current horrible mess that are the existing Java Date and Calendar classes. It's date handling done right.

EDIT: It's not 2009 any more, and Java 8's been out for ages. Use Java 8's built in java.time classes which are based on Joda Time, as Basil Bourque mentions above. In this case you'll want the Period class, and here's Oracle's tutorial on how to use it.

Since Java 8

NOTE: All, but one, Date's constructors are deprecated. Most of the Date's methods are deprecated. REF: Date: Deprecated Methods. All, but Date::from(Instant), static methods are deprecated.

So, since java 8 consider using Instant (immutable, thread-safe, leap-seconds aware) type rather than Date. REF: Instant

  static final LocalTime MARKETS_OPEN = LocalTime.of(07, 00);
  static final LocalTime MARKETS_CLOSE = LocalTime.of(20, 00);

    // Instant utcTime = testDate.toInstant();
    var bigAppleTime = ZonedDateTime.ofInstant(utcTime, ZoneId.of("America/New_York"));

within the range INCLUSIVE:

    return !bigAppleTime.toLocalTime().isBefore(MARKETS_OPEN)
        && !bigAppleTime.toLocalTime().isAfter(MARKETS_CLOSE);

within the range EXCLUSIVE:

    return bigAppleTime.toLocalTime().isAfter(MARKETS_OPEN)
        && bigAppleTime.toLocalTime().isBefore(MARKETS_CLOSE);

An easy way is to convert the dates into milliseconds after January 1, 1970 (use Date.getTime()) and then compare these values.

if you want inclusive comparison with LocalDate then use this code.

LocalDate from = LocalDate.of(2021,8,1);
LocalDate to = LocalDate.of(2021,8,1);
LocalDate current = LocalDate.of(2021,8,1);

boolean isDateInRage = ( ! (current.isBefore(from.minusDays(1)) && current.isBefore(to.plusDays(1))) );

For covering my case -> I've got a range start & end date, and dates list that can be as partly in provided range, as fully (overlapping).

Solution covered with tests:

/**
 * Check has any of quote work days in provided range.
 *
 * @param startDate inclusively
 * @param endDate   inclusively
 *
 * @return true if any in provided range inclusively
 */
public boolean hasAnyWorkdaysInRange(LocalDate startDate, LocalDate endDate) {
    if (CollectionUtils.isEmpty(workdays)) {
        return false;
    }

    LocalDate firstWorkDay = getFirstWorkDay().getDate();
    LocalDate lastWorkDay = getLastWorkDay().getDate();

    return (firstWorkDay.isBefore(endDate) || firstWorkDay.equals(endDate))
            && (lastWorkDay.isAfter(startDate) || lastWorkDay.equals(startDate));
}

  public class TestDate {

    public static void main(String[] args) {
    // TODO Auto-generated method stub

    String fromDate = "18-FEB-2018";
    String toDate = "20-FEB-2018";

    String requestDate = "19/02/2018";  
    System.out.println(checkBetween(requestDate,fromDate, toDate));
}

public static boolean checkBetween(String dateToCheck, String startDate, String endDate) {
    boolean res = false;
    SimpleDateFormat fmt1 = new SimpleDateFormat("dd-MMM-yyyy"); //22-05-2013
    SimpleDateFormat fmt2 = new SimpleDateFormat("dd/MM/yyyy"); //22-05-2013
    try {
     Date requestDate = fmt2.parse(dateToCheck);
     Date fromDate = fmt1.parse(startDate);
     Date toDate = fmt1.parse(endDate);
     res = requestDate.compareTo(fromDate) >= 0 && requestDate.compareTo(toDate) <=0;
    }catch(ParseException pex){
        pex.printStackTrace();
    }
    return res;
   }
 }

Adding new solution if the date is equals to start date:

boolean isWithinRange(Date testDate) {
   return !(testDate.before(startDate) || testDate.after(endDate));
}

Solution

return testDate.equals(startDate) || (testDate.after(startDate) && 
testDate.before(endDate)) || testDate.equals(endDate);

    public boolean isBetween(LocalDate target, LocalDate min, LocalDate max) {
    if (target == null || min == null || max == null) {
        throw new IllegalArgumentException("paramettres can't be null");
    }

    return target.compareTo(min) >= 0 && target.compareTo(max) <= 0;
}

A solution will be to check date with after and before method. If is required to consider inclusive endDate, testDate.before(endDate) returns false when testDate and endDate are the same day, we can use "apache commons lang" package to verify this (org.apache.commons.lang.time.DateUtils)

import org.apache.commons.lang.time.DateUtils;

boolean isWithinRange(Date testDate) {
    return   testDate.after(startDate) && (testDate.before(endDate) || DateUtils.isSameDay(testDate, endDate));
}

google guava

Range.closed(start, end)
            .isConnected(Range.closed(now, now));