public long convertToTimeBucket(Step step, String dateStr) {
        verifyDateTimeString(step, dateStr);
        dateStr = dateStr.replaceAll(Const.LINE, Const.EMPTY_STRING);
        dateStr = dateStr.replaceAll(Const.SPACE, Const.EMPTY_STRING);
        return Long.parseLong(dateStr);
    }
Convert date in `yyyy-MM-dd HHmmss` style to `yyyyMMddHHmmss` no matter the precision. Such as, in day precision,
this covert `yyyy-MM-dd` style to `yyyyMMdd`.
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/query/DurationUtils.java