计算开始日期到结束日期的总天数

 结构

<el-form-item label="计划开始时间" required prop="StartTime">
   <el-date-picker
      type="date"
      v-model="ruleForm.StartTime"
      :disabled-date="StartTime"
      placeholder="计划开始时间" />
</el-form-item>
<el-form-item label="计划结束时间" required prop="EndTime">
    <el-date-picker
       type="date"
       v-model="ruleForm.EndTime"
       :disabled-date="EndTime"
       placeholder="计划结束时间" />
</el-form-item>

 逻辑

const StartTime= (time) => {
    return time < ruleForm.StartTime
}
const EndTime= (time) => {
  if (ruleForm.EndTime) {
    return time > ruleForm.EndTime
  }
}
ruleForm.TotalDays = computed(() => {
  return Math.ceil((new Date(ruleForm.EndTime).getTime() - new Date(ruleForm.StartTime).getTime()) / (1000 * 60 * 60 * 24))
})