日付操作.ts

DateUtils.ts

export function nextMonth(date: Date, resetDate: boolean = false): Date {
  return addOfMonthBy(date, 1, resetDate)
}

export function lastMonth(date: Date, resetDate: boolean = false): Date {
  return subtractOfMonthBy(date, 1, resetDate)
}

export function lastYear(date: Date, resetMonth: boolean = false, resetDate: boolean = false): Date {
  return subtractOfYearBy(date, 1, resetMonth, resetDate);
}

export function lastDayOfTheMonth(date: Date): Date {
  const nextMonth1 = nextMonth(date, true);
  nextMonth1.setDate(nextMonth1.getDate() - 1)
  return nextMonth1
}

export function firstDayOfTheMonth(date: Date): Date {
  const cloneDate = new Date(date);
  cloneDate.setDate(1);
  return cloneDate;
}

export function addOfMonthBy(date: Date, add: number, resetDate: boolean = false): Date {
  const cloneDate = new Date(date);
  if (resetDate) {
    cloneDate.setDate(1)
  }
  cloneDate.setMonth(date.getMonth() + add);
  return cloneDate;
}

export function subtractOfMonthBy(date: Date, subtract: number, resetDate: boolean = false): Date {
  const cloneDate = new Date(date);
  if (resetDate) {
    cloneDate.setDate(1)
  }
  cloneDate.setMonth(date.getMonth() - subtract);
  return cloneDate;
}

export function subtractOfYearBy(date: Date, subtract: number, resetMonth: boolean = false, resetDate: boolean = false): Date {
  const cloneDate = new Date(date);
  if (resetMonth) {
    cloneDate.setMonth(0)
  }
  if (resetDate) {
    cloneDate.setDate(1)
  }
  cloneDate.setFullYear(cloneDate.getFullYear() - subtract, cloneDate.getMonth(), cloneDate.getDate())
  return cloneDate;
}

export function addOfYearBy(date: Date, add: number, resetMonth: boolean = false, resetDate: boolean = false): Date {
  const cloneDate = new Date(date);
  if (resetMonth) {
    cloneDate.setMonth(0)
  }
  if (resetDate) {
    cloneDate.setDate(1)
  }
  cloneDate.setFullYear(cloneDate.getFullYear() + add, cloneDate.getMonth(), cloneDate.getDate())
  return cloneDate;
}

export function firstDayOfTheYear(date: Date): Date {
  const cloneDate = new Date(date);
  cloneDate.setFullYear(date.getFullYear(), 0, 1);
  return cloneDate;
}

export function lastDayOfTheYear(date: Date, calculate: boolean = false): Date {
  const cloneDate = new Date(date);
  if (!calculate) {
    cloneDate.setFullYear(date.getFullYear(), 11, 31)
    return cloneDate;
  }
  const firstDayOfTheYear1 = firstDayOfTheYear(cloneDate);
  firstDayOfTheYear1.setDate(-1)
  return firstDayOfTheYear1;
}