使用Java util.Date，这里是我所做的。

    public static boolean checkTimeOverlaps(Date startDate1, Date endDate1, Date startDate2, Date endDate2)
    {
        if (startDate1 == null || endDate1 == null || startDate2 == null || endDate2 == null)
           return false;

        if ((startDate1.getTime() <= endDate2.getTime()) && (startDate2.getTime() <= endDate1.getTime()))
           return true;

        return false;
    }

我认为，在以下情况下，两个范围重叠就足够了：

(StartDate1 <= EndDate2) and (StartDate2 <= EndDate1)

我会的

StartDate1.IsBetween(StartDate2, EndDate2) || EndDate1.IsBetween(StartDate2, EndDate2)

IsBetween是这样的

    public static bool IsBetween(this DateTime value, DateTime left, DateTime right) {
        return (value > left && value < right) || (value < left && value > right);
    }

简单的解决方案：

compare the two dates: 
    A = the one with smaller start date, B = the one with bigger start date
if(A.end < B.start)
    return false
return true

这是我使用moment.js的javascript解决方案：

// Current row dates
var dateStart = moment("2014-08-01", "YYYY-MM-DD");
var dateEnd = moment("2014-08-30", "YYYY-MM-DD");

// Check with dates above
var rangeUsedStart = moment("2014-08-02", "YYYY-MM-DD");
var rangeUsedEnd = moment("2014-08-015", "YYYY-MM-DD");

// Range covers other ?
if((dateStart <= rangeUsedStart) && (rangeUsedEnd <= dateEnd)) {
    return false;
}
// Range intersects with other start ?
if((dateStart <= rangeUsedStart) && (rangeUsedStart <= dateEnd)) {
    return false;
}
// Range intersects with other end ?
if((dateStart <= rangeUsedEnd) && (rangeUsedEnd <= dateEnd)) {
    return false;
}

// All good
return true;

对于ruby，我也发现了这一点：

class Interval < ActiveRecord::Base

  validates_presence_of :start_date, :end_date

  # Check if a given interval overlaps this interval    
  def overlaps?(other)
    (start_date - other.end_date) * (other.start_date - end_date) >= 0
  end

  # Return a scope for all interval overlapping the given interval, including the given interval itself
  named_scope :overlapping, lambda { |interval| {
    :conditions => ["id <> ? AND (DATEDIFF(start_date, ?) * DATEDIFF(?, end_date)) >= 0", interval.id, interval.end_date, interval.start_date]
  }}

end

在这里找到它，解释很好->http://makandracards.com/makandra/984-test-if-two-date-ranges-overlap-in-ruby-or-rails