ZonedDateTime zdt = ZonedDateTime.now(ZoneOffset.UTC);

        int now15Minute = zdt.getMinute() / P15MINUTE * P15MINUTE;
　　　　　//instant当前时刻的下一个15分钟时间点

        Instant instant = ZonedDateTime

                .of(zdt.getYear(), zdt.getMonthValue(), zdt.getDayOfMonth(),

                        zdt.getHour(), now15Minute, 0, 0, ZoneOffset.UTC)

                .toInstant().plus(Duration.ofMinutes(P15MINUTE));