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Date Comparisons

Holy Time provides comprehensive methods for comparing dates and checking temporal conditions.

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Basic Comparisons

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isAfter

Check if one date is after another: 
import HolyTime from 'holy-time'

const earlier = new HolyTime('2023-01-01T00:00:00.000Z')
const later = new HolyTime('2023-01-02T00:00:00.000Z')

earlier.isAfter(later)  // false
later.isAfter(earlier)  // true

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Static Method

HolyTime.isAfter('2023-01-02', '2023-01-01')  // true

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isBefore

Check if one date is before another: 
const earlier = new HolyTime('2023-01-01T00:00:00.000Z')
const later = new HolyTime('2023-01-02T00:00:00.000Z')

earlier.isBefore(later)  // true
later.isBefore(earlier)  // false

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Static Method

HolyTime.isBefore('2023-01-01', '2023-01-02')  // true

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Same Time Comparison

Check if two dates represent the same moment or fall within the same time period: 
const date1 = new HolyTime('2023-01-01T12:30:00.000Z')
const date2 = new HolyTime('2023-01-01T14:45:00.000Z')

// Exact match
date1.isSame(date2, 'millisecond')  // false

// Same day
date1.isSame(date2, 'day')  // true

// Same month
date1.isSame(date2, 'month')  // true

// Same year
date1.isSame(date2, 'year')  // true

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Supported Units

date1.isSame(date2, 'millisecond')  // Exact timestamp match

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Static Method

HolyTime.isSame('2023-01-01', '2023-01-15', 'month')  // true

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Relative to Current Time

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isFuture

Check if a date is in the future: 
const tomorrow = HolyTime.in(1, 'days')
const yesterday = HolyTime.in(-1, 'days')

tomorrow.isFuture()   // true
yesterday.isFuture()  // false

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Static Method

HolyTime.isFuture('2030-01-01')  // true

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isPast

Check if a date is in the past: 
const yesterday = HolyTime.in(-1, 'days')
const tomorrow = HolyTime.in(1, 'days')

yesterday.isPast()  // true
tomorrow.isPast()   // false

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Static Method

HolyTime.isPast('2020-01-01')  // true

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Special Checks

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isWeekend

Check if a date falls on a weekend (Saturday or Sunday): 
const weekday = new HolyTime('2023-01-04T01:00:00.000Z')  // Wednesday
const weekend = new HolyTime('2023-01-07T00:00:00.000Z')  // Saturday

weekday.isWeekend()  // false
weekend.isWeekend()  // true

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Static Method

HolyTime.isWeekend('2023-01-07')  // true (Saturday)
HolyTime.isWeekend('2023-01-08')  // true (Sunday)
HolyTime.isWeekend('2023-01-09')  // false (Monday)

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isLeapYear

Check if a year is a leap year: 
HolyTime.isLeapYear(2024)  // true
HolyTime.isLeapYear(2023)  // false
HolyTime.isLeapYear(2000)  // true
HolyTime.isLeapYear(1900)  // false

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Instance Method

const date = new HolyTime('2024-06-15')
date.isLeapYear()  // true
Leap year rules: divisible by 4, except century years must be divisible by 400.

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Min and Max

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Finding Maximum Date

Get the latest date from multiple dates: 
const date1 = new HolyTime('2023-01-01T01:02:03.000Z')
const date2 = new HolyTime('2023-01-01T01:02:04.000Z')
const date3 = '2023-01-01T01:02:02.000Z'

const latest = HolyTime.max(date1, date2, date3)
// Returns: date2 (2023-01-01T01:02:04.000Z)

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Finding Minimum Date

Get the earliest date from multiple dates: 
const date1 = new HolyTime('2023-01-01T01:02:03.000Z')
const date2 = new HolyTime('2023-01-01T01:02:04.000Z')
const date3 = '2023-01-01T01:02:02.000Z'

const earliest = HolyTime.min(date1, date2, date3)
// Returns: date3 as HolyTime (2023-01-01T01:02:02.000Z)

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Real-World Example

// Find the most recent update
const updates = [
  '2023-06-01',
  '2023-06-15',
  '2023-06-10'
]

const mostRecent = HolyTime.max(...updates)

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Time Between Dates

Calculate duration between two dates: 
const start = new HolyTime('2023-01-01T00:00:00.000Z')
const end = new HolyTime('2023-01-01T01:00:00.000Z')

const duration = HolyTime.between(start, end)
duration.in('hours')        // 1
duration.in('minutes')      // 60
duration.in('milliseconds') // 3600000

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Format Duration

const start = new HolyTime('2023-01-01')
const end = new HolyTime('2023-01-03')

const duration = HolyTime.between(start, end)
duration.format('short')  // "2d"
duration.format('long')   // "2 days"

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Practical Examples

function isBusinessHours(date: HolyTime): boolean {
  if (date.isWeekend()) return false
  
  const hour = date.get('hour')
  return hour >= 9 && hour < 17
}

const now = HolyTime.now()
isBusinessHours(now)  // true or false

function findNearest(target: HolyTime, dates: HolyTime[]): HolyTime {
  return dates.reduce((nearest, current) => {
    const nearestDiff = HolyTime.between(target, nearest).in('milliseconds')
    const currentDiff = HolyTime.between(target, current).in('milliseconds')
    return currentDiff < nearestDiff ? current : nearest
  })
}

function isInRange(
  date: HolyTime,
  start: HolyTime,
  end: HolyTime
): boolean {
  return date.isAfter(start) && date.isBefore(end)
}

const now = HolyTime.now()
const rangeStart = HolyTime.in(-7, 'days')
const rangeEnd = HolyTime.in(7, 'days')

isInRange(now, rangeStart, rangeEnd)  // true

const isValid = new HolyTime('2022-10-20')
  .isAfter(
    HolyTime.subtract(
      HolyTime.in(4, 'days'), 
      8, 'weeks'
    )
  )
// Checks if Oct 20, 2022 is after (4 days from now - 8 weeks)

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