java - Integer Time Intervals -

this question more of math problem (sorry, i'm not in math).

i have time represented integer

for example

700 (means 7:00)  1330 (means 13:30)  2359 (means 23:59) 

i have starting time , ending time , want create 15 minutes intervals between them. example

int start = 700; int end = 1300; 

i want loop on starting time increment 15 minutes , jump on 60 next hundred. example 700, 715, 730, 745, 800, 815, 830.. etc.

i can create creating calendar object , parse integer simpledateformat, add time calendar, increase minutes, , parse hours , minutes integer. way long it, there should simple mathematical way perform more efficiently.

if must use integers, or decided to, can create method "plusminutes", like:

public int plusminutes (int time, int minutes) {     int auxminutes = time % 60;     auxminutes += minutes;     time += 100 * (seconds / 60);     time = 100 * (time / 100); // set last 2 digits 0     time += auxminutes % 60;      return time; } 

another option (better in opinion) create method "tominutes" , method "toencoded", like:

public int tominutes (int encoded) {     int minutes = encoded % 100;     minutes += (encoded / 100) * 60;     return minutes; }  public int toencoded (int minutes) {     int encoded = minutes % 60;     encoded += (minutes / 60) * 100;     return encoded; } 

note: not 100% sure if code works, haven't tested, should general idea.

edit: , problem when using last option, have like:

int encoded = 1330; int plusminutes = 45;  int minutes = tominutes(encoded); minutes += plusminutes;  encoded = toencoded(minutes);