Angular 在角度2中比较2次

如何将输入的时间与当前时间进行比较，并在angular 2中显示警报/弹出消息 如果当前时间大于输入的时间，则应显示弹出消息

ts文件：

let currentDate = new Date();
let pickdate = $('#pickTime');
let commingOn = $('#startClock');
let option: Options = {
    title: 'Start Date',
    format: 'DD, MM dd, yyyy',
    startDate: currentDate
};
let clock = {
    autoclose: true,
    twelvehour: false,
    'default': 'now'
};
pickdate.datepicker(option).on('changeDate', (selected) = > {
    this.dateProcess(selected.date);
});
startClock.clockpicker(clock).on('change', () = > {
    this.timeProcess();
});

HTML

开始：
看来你也应该把日期考虑进去，因为如果现在是下午3点，昨天晚上9点就更早了…@HereticMonkey，我正在考虑日期和时间
<div id="startDiv" style="display: flex;">
    <h5 >Start: </h5>
    <div class='input-group date' id='pickTime' #dateCreate
        <input type='text' class="form-control" style="cursor: text;" />
        <span class="group">
            <span class="glyphicon glyphicon-calendar"></span>
        </span>
    </div>
    <div class="input-group clockpicker" id="startClock"
        <input type="text" class="form-control"  id="clockValue">
        <span class="group>
            <span class="glyphicon glyphicon-time"></span>
        </span>
    </div>
</div>