/datum/unit_test/hours_calculations/start()
	assert_eq(add_minutes("12:00", 9), "12:09")
	assert_eq(add_minutes("12:00", 59), "12:59")
	assert_eq(add_minutes("12:00", 60), "13:00")
	assert_eq(add_minutes("12:00", 61), "13:01")
	assert_eq(add_minutes("12:00", 119), "13:59")
	assert_eq(add_minutes("12:00", 120), "14:00")
	assert_eq(add_minutes("12:00", 121), "14:01")

	assert_eq(add_minutes("12:05", 9), "12:14")
	assert_eq(add_minutes("12:05", 59), "13:04")
	assert_eq(add_minutes("12:05", 60), "13:05")
	assert_eq(add_minutes("12:05", 61), "13:06")
	assert_eq(add_minutes("12:05", 119), "14:04")
	assert_eq(add_minutes("12:05", 120), "14:05")
	assert_eq(add_minutes("12:05", 121), "14:06")

	assert_eq(add_minutes("12:15", 9), "12:24")
	assert_eq(add_minutes("12:15", 59), "13:14")
	assert_eq(add_minutes("12:15", 60), "13:15")
	assert_eq(add_minutes("12:15", 61), "13:16")
	assert_eq(add_minutes("12:15", 119), "14:14")
	assert_eq(add_minutes("12:15", 120), "14:15")
	assert_eq(add_minutes("12:15", 121), "14:16")

	assert_eq(add_minutes("12:59", 9), "13:08")
	assert_eq(add_minutes("12:59", 59), "13:58")
	assert_eq(add_minutes("12:59", 60), "13:59")
	assert_eq(add_minutes("12:59", 61), "14:00")
	assert_eq(add_minutes("12:59", 119), "14:58")
	assert_eq(add_minutes("12:59", 120), "14:59")
	assert_eq(add_minutes("12:59", 121), "15:00")