public EarthTime subEarthTime(EarthTime pt) {
// The easiest way to deal with subtraction is to work with minutes, since
// there wont be unit conversion issues. After converting and doing
// the math, we convert back into proper clock units using our clockFriend.
int totalMinute =
(((this.getYears() * 365 * 24 * 60)
+ (this.getDays() * 24 * 60)
+ (this.getHours() * 60)
+ (this.getMinutes()))
- ((pt.getYears() * 365 * 24 * 60)
+ (pt.getDays() * 24 * 60)
+ (pt.getHours() * 60)
+ (pt.getMinutes())));
return clockFriend(totalMinute);
}
public EarthTime addEarthTime(EarthTime pt) {
// Adds two EarthTime objects together and adjusts for proper clock-time
// (i.e., clocks don't represent 61 minutes, but rather and 1 hour and 1 minute)
int totalYears = this.getYears() + pt.getYears();
int totalDays = this.getDays() + pt.getDays();
int totalHours = this.getHours() + pt.getHours();
int totalMinute = this.getMinutes() + pt.getMinutes();
totalHours = totalHours + (totalMinute / 60);
totalMinute = totalMinute % 60;
totalDays = totalDays + (totalHours / 24);
totalHours = totalHours % 24;
totalYears = totalYears + (totalDays / 365);
totalDays = totalDays % 365;
EarthTime newpt = new EarthTime(totalYears, totalDays, totalHours, totalMinute);
return newpt;
}