LocalDate Get the first and last day of the current month and get the start time of the day

        // 获取当前月的第一天
        LocalDate firstDay = LocalDate.now().with(TemporalAdjusters.firstDayOfMonth());
        // 获取当前月的最后一天
        LocalDate lastDay = LocalDate.now().with(TemporalAdjusters.lastDayOfMonth());