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What I am trying to achieve is to get all entries from an array in a range of the last 30 days and push this into a new array which I can work with afterwards.

My array (this.trades) looks like this:

{
id: "95",
datum: "2020-03-11",
trade: "EUR/USD BUY",
aktion: "closed",
pips: "10"
},
{
id: "94",
datum: "2020-06-09",
trade: "GBP/USD BUY",
aktion: "TP Hit",
pips: "65"
},
{
id: "93",
datum: "2020-06-08",
trade: "NZD/USD SELL",
aktion: "SL Hit",
pips: "-57"
},

datum is the german word for date. the array is pretty long (filled with 95 entries over the past half year).

So my desired output would be:

• to sort the Array by its date (this.trades.datum)
• to extract all the entries within the last 30 days
• and finally push this into a new array to work with (containing all the other keys)

I'm working in a vuejs project and have the opportunity to use puted properties for calculating, i'm also using momentjs library.

Here is my current function, where i convert datum into dateobjects: But i want to get only the entries from the last 30 days.

 chartDatumMonth() {
      let data = this.trades;
      data.forEach(d => {
        d.dateObj = moment(d.datum);
      });
      console.log(data);
      return data;
    },

console output:

(80) [{…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, __ob__: Observer]
0:
aktion: (...)
dateObj: Moment
_d: Wed Aug 05 2020 00:00:00 GMT+0200 (Mitteleuropäische Sommerzeit) {}
_f: "YYYY-MM-DD"
_i: "2020-08-05"
_isAMomentObject: true
_isUTC: false
_isValid: true
_locale: Locale {_calendar: {…}, _longDateFormat: {…}, _invalidDate: "Invalid date", _dayOfMonthOrdinalParse: /\d{1,2}(th|st|nd|rd)/, ordinal: ƒ, …}
_pf: {empty: false, unusedTokens: Array(0), unusedInput: Array(0), overflow: -1, charsLeftOver: 0, …}
__proto__: Object
datum: "2020-08-05"
id: (...)
pips: (...)
trade: (...)
__ob__: Observer {value: {…}, dep: Dep, vmCount: 0}
get aktion: ƒ reactiveGetter()
set aktion: ƒ reactiveSetter(newVal)
get datum: ƒ reactiveGetter()
set datum: ƒ reactiveSetter(newVal)
get id: ƒ reactiveGetter()
set id: ƒ reactiveSetter(newVal)
get pips: ƒ reactiveGetter()
set pips: ƒ reactiveSetter(newVal)
get trade: ƒ reactiveGetter()
set trade: ƒ reactiveSetter(newVal)
__proto__: Object
1:
aktion: (...)
dateObj: Moment {_isAMomentObject: true, _i: "2020-08-04", _f: "YYYY-MM-DD", _isUTC: false, _pf: {…}, …}
datum: "2020-08-04"

What I am trying to achieve is to get all entries from an array in a range of the last 30 days and push this into a new array which I can work with afterwards.

My array (this.trades) looks like this:

{
id: "95",
datum: "2020-03-11",
trade: "EUR/USD BUY",
aktion: "closed",
pips: "10"
},
{
id: "94",
datum: "2020-06-09",
trade: "GBP/USD BUY",
aktion: "TP Hit",
pips: "65"
},
{
id: "93",
datum: "2020-06-08",
trade: "NZD/USD SELL",
aktion: "SL Hit",
pips: "-57"
},

datum is the german word for date. the array is pretty long (filled with 95 entries over the past half year).

So my desired output would be:

• to sort the Array by its date (this.trades.datum)
• to extract all the entries within the last 30 days
• and finally push this into a new array to work with (containing all the other keys)

I'm working in a vuejs project and have the opportunity to use puted properties for calculating, i'm also using momentjs library.

Here is my current function, where i convert datum into dateobjects: But i want to get only the entries from the last 30 days.

 chartDatumMonth() {
      let data = this.trades;
      data.forEach(d => {
        d.dateObj = moment(d.datum);
      });
      console.log(data);
      return data;
    },

console output:

(80) [{…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, __ob__: Observer]
0:
aktion: (...)
dateObj: Moment
_d: Wed Aug 05 2020 00:00:00 GMT+0200 (Mitteleuropäische Sommerzeit) {}
_f: "YYYY-MM-DD"
_i: "2020-08-05"
_isAMomentObject: true
_isUTC: false
_isValid: true
_locale: Locale {_calendar: {…}, _longDateFormat: {…}, _invalidDate: "Invalid date", _dayOfMonthOrdinalParse: /\d{1,2}(th|st|nd|rd)/, ordinal: ƒ, …}
_pf: {empty: false, unusedTokens: Array(0), unusedInput: Array(0), overflow: -1, charsLeftOver: 0, …}
__proto__: Object
datum: "2020-08-05"
id: (...)
pips: (...)
trade: (...)
__ob__: Observer {value: {…}, dep: Dep, vmCount: 0}
get aktion: ƒ reactiveGetter()
set aktion: ƒ reactiveSetter(newVal)
get datum: ƒ reactiveGetter()
set datum: ƒ reactiveSetter(newVal)
get id: ƒ reactiveGetter()
set id: ƒ reactiveSetter(newVal)
get pips: ƒ reactiveGetter()
set pips: ƒ reactiveSetter(newVal)
get trade: ƒ reactiveGetter()
set trade: ƒ reactiveSetter(newVal)
__proto__: Object
1:
aktion: (...)
dateObj: Moment {_isAMomentObject: true, _i: "2020-08-04", _f: "YYYY-MM-DD", _isUTC: false, _pf: {…}, …}
datum: "2020-08-04"

• javascript
• arrays
• sorting
• date

Share Improve this question Follow edited Aug 8, 2020 at 10:36 Oliver Borner asked Aug 8, 2020 at 10:12 Oliver BornerOliver Borner 3311 silver badge55 bronze badges 7

• I tried this to convert the array into dateobjects: let data = this.trades; data.forEach(d => { d.dateObj = moment(d.datum); }); but then i have to reduce the array by its last 30 Days, that's where i stuck at the moment. Thank you! – Oliver Borner Commented Aug 8, 2020 at 10:19
• Edit the question to give a minimal reproducible example. – jonrsharpe Commented Aug 8, 2020 at 10:19
• You don't seem to have made any attempt to filter the list, maybe read developer.mozilla/en-US/docs/Web/JavaScript/Reference/… – jonrsharpe Commented Aug 8, 2020 at 10:40
• Thank you, i will have a look into it. So you mean, i have to filter the list by date first. But how do i give it the range of 30 days? That's my question. – Oliver Borner Commented Aug 8, 2020 at 10:43
• That's not currently what's asked in the question. Read the moment docs if you want to find out how to manipulate a date. – jonrsharpe Commented Aug 8, 2020 at 10:45

 |  Show 2 more ments

3 Answers 3

Sorted by: Reset to default 5

In ECMAScript, dates in the format "YYYY-MM-DD" are parsed as UTC. When creating a date using new Date(), it is based on the local date and also has a ponent for the current time so when paring values like "30 days ago" you must normalise everything to the same datum. In this case, UTC will be the simplest.

Otherwise, you'll get errors if the code is run near the start or end of the local day due to timezone offset differences where the UTC date is behind or ahead of the local date. The time ponent also should be set to zero.

The following creates a date for n days ago, then filters the dataset and sorts it. Since the supplied data is a few months old, I've made daysAgo a parameter that is passed to the function. Also, the sort uses localCompare as it's more efficient than creating and paring Date objects, and works well with ISO 8601 formatted dates.

let data = [{
    id: "95",
    datum: "2020-03-11",
    trade: "EUR/USD BUY",
    aktion: "closed",
    pips: "10"
  },
  {
    id: "94",
    datum: "2020-06-09",
    trade: "GBP/USD BUY",
    aktion: "TP Hit",
    pips: "65"
  }, {
    id: "93",
    datum: "2020-06-08",
    trade: "NZD/USD SELL",
    aktion: "SL Hit",
    pips: "-57"
  }];
  
function getDaysAgoData(data, daysAgo) {
  // Get current date
  let t = new Date();
  // Create UTC date for daysAgo
  let d = new Date(Date.UTC(t.getFullYear(), t.getMonth(), t.getDate() - daysAgo));
  // Filter and sort data
  return data.filter(item => new Date(item.datum) >= d)
             .sort((a, b) => a.datum.localeCompare(b.datum));
}

console.log(getDaysAgoData(data, 90));

This should get you going

const list = [{
    id: "95",
    datum: "2020-03-11",
    trade: "EUR/USD BUY",
    aktion: "closed",
    pips: "10"
  },
  {
    id: "94",
    datum: "2020-06-09",
    trade: "GBP/USD BUY",
    aktion: "TP Hit",
    pips: "65"
  },
  {
    id: "93",
    datum: "2020-08-01",
    trade: "NZD/USD SELL",
    aktion: "SL Hit",
    pips: "-57"
  },
]


const currentDate = new Date();
const currentDateTime = currentDate.getTime();
const last30DaysDate = new Date(currentDate.setDate(currentDate.getDate() - 30));
const last30DaysDateTime = last30DaysDate.getTime();

const last30DaysList = list.filter(x => {
  const elementDateTime = new Date(x.datum).getTime();
  if (elementDateTime <= currentDateTime && elementDateTime > last30DaysDateTime) {
    return true;
  }
  return false
}).sort((a, b) => {
  return new Date(b.datum) - new Date(a.datum);
});

console.log(last30DaysList)

Edit: Now the array is sorted (in first version I forgot this);

let arr = [{
id: "95",
datum: "2020-03-11",
trade: "EUR/USD BUY",
aktion: "closed",
pips: "10"
},
{
id: "94",
datum: "2020-07-20",
trade: "GBP/USD BUY",
aktion: "TP Hit",
pips: "65"
},
{
id: "93",
datum: "2020-06-18",
trade: "NZD/USD SELL",
aktion: "SL Hit",
pips: "-57"
},
{
id: "92",
datum: "2020-07-15",
trade: "GBP/USD BUY",
aktion: "TP Hit",
pips: "65"
},];

const today = new Date ();
result = arr.filter(obj => {
    const date = new Date(obj.datum);
    const diffTime = Math.abs(today - date);
    const diffDays = Math.ceil(diffTime / (1000 * 60 * 60 * 24)); 
    return (diffDays <=30);
});

result.sort((a,b) => {
    a = new Date(a.datum);
  b= new Date(b.datum);
  return (a<b) ? -1 : (a>b) ? 1 : 0; 
})
console.log(result);

What I am trying to achieve is to get all entries from an array in a range of the last 30 days and push this into a new array which I can work with afterwards.

My array (this.trades) looks like this:

{
id: "95",
datum: "2020-03-11",
trade: "EUR/USD BUY",
aktion: "closed",
pips: "10"
},
{
id: "94",
datum: "2020-06-09",
trade: "GBP/USD BUY",
aktion: "TP Hit",
pips: "65"
},
{
id: "93",
datum: "2020-06-08",
trade: "NZD/USD SELL",
aktion: "SL Hit",
pips: "-57"
},

datum is the german word for date. the array is pretty long (filled with 95 entries over the past half year).

So my desired output would be:

• to sort the Array by its date (this.trades.datum)
• to extract all the entries within the last 30 days
• and finally push this into a new array to work with (containing all the other keys)

I'm working in a vuejs project and have the opportunity to use puted properties for calculating, i'm also using momentjs library.

Here is my current function, where i convert datum into dateobjects: But i want to get only the entries from the last 30 days.

 chartDatumMonth() {
      let data = this.trades;
      data.forEach(d => {
        d.dateObj = moment(d.datum);
      });
      console.log(data);
      return data;
    },

console output:

(80) [{…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, __ob__: Observer]
0:
aktion: (...)
dateObj: Moment
_d: Wed Aug 05 2020 00:00:00 GMT+0200 (Mitteleuropäische Sommerzeit) {}
_f: "YYYY-MM-DD"
_i: "2020-08-05"
_isAMomentObject: true
_isUTC: false
_isValid: true
_locale: Locale {_calendar: {…}, _longDateFormat: {…}, _invalidDate: "Invalid date", _dayOfMonthOrdinalParse: /\d{1,2}(th|st|nd|rd)/, ordinal: ƒ, …}
_pf: {empty: false, unusedTokens: Array(0), unusedInput: Array(0), overflow: -1, charsLeftOver: 0, …}
__proto__: Object
datum: "2020-08-05"
id: (...)
pips: (...)
trade: (...)
__ob__: Observer {value: {…}, dep: Dep, vmCount: 0}
get aktion: ƒ reactiveGetter()
set aktion: ƒ reactiveSetter(newVal)
get datum: ƒ reactiveGetter()
set datum: ƒ reactiveSetter(newVal)
get id: ƒ reactiveGetter()
set id: ƒ reactiveSetter(newVal)
get pips: ƒ reactiveGetter()
set pips: ƒ reactiveSetter(newVal)
get trade: ƒ reactiveGetter()
set trade: ƒ reactiveSetter(newVal)
__proto__: Object
1:
aktion: (...)
dateObj: Moment {_isAMomentObject: true, _i: "2020-08-04", _f: "YYYY-MM-DD", _isUTC: false, _pf: {…}, …}
datum: "2020-08-04"

What I am trying to achieve is to get all entries from an array in a range of the last 30 days and push this into a new array which I can work with afterwards.

My array (this.trades) looks like this:

{
id: "95",
datum: "2020-03-11",
trade: "EUR/USD BUY",
aktion: "closed",
pips: "10"
},
{
id: "94",
datum: "2020-06-09",
trade: "GBP/USD BUY",
aktion: "TP Hit",
pips: "65"
},
{
id: "93",
datum: "2020-06-08",
trade: "NZD/USD SELL",
aktion: "SL Hit",
pips: "-57"
},

datum is the german word for date. the array is pretty long (filled with 95 entries over the past half year).

So my desired output would be:

• to sort the Array by its date (this.trades.datum)
• to extract all the entries within the last 30 days
• and finally push this into a new array to work with (containing all the other keys)

I'm working in a vuejs project and have the opportunity to use puted properties for calculating, i'm also using momentjs library.

Here is my current function, where i convert datum into dateobjects: But i want to get only the entries from the last 30 days.

 chartDatumMonth() {
      let data = this.trades;
      data.forEach(d => {
        d.dateObj = moment(d.datum);
      });
      console.log(data);
      return data;
    },

console output:

(80) [{…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, __ob__: Observer]
0:
aktion: (...)
dateObj: Moment
_d: Wed Aug 05 2020 00:00:00 GMT+0200 (Mitteleuropäische Sommerzeit) {}
_f: "YYYY-MM-DD"
_i: "2020-08-05"
_isAMomentObject: true
_isUTC: false
_isValid: true
_locale: Locale {_calendar: {…}, _longDateFormat: {…}, _invalidDate: "Invalid date", _dayOfMonthOrdinalParse: /\d{1,2}(th|st|nd|rd)/, ordinal: ƒ, …}
_pf: {empty: false, unusedTokens: Array(0), unusedInput: Array(0), overflow: -1, charsLeftOver: 0, …}
__proto__: Object
datum: "2020-08-05"
id: (...)
pips: (...)
trade: (...)
__ob__: Observer {value: {…}, dep: Dep, vmCount: 0}
get aktion: ƒ reactiveGetter()
set aktion: ƒ reactiveSetter(newVal)
get datum: ƒ reactiveGetter()
set datum: ƒ reactiveSetter(newVal)
get id: ƒ reactiveGetter()
set id: ƒ reactiveSetter(newVal)
get pips: ƒ reactiveGetter()
set pips: ƒ reactiveSetter(newVal)
get trade: ƒ reactiveGetter()
set trade: ƒ reactiveSetter(newVal)
__proto__: Object
1:
aktion: (...)
dateObj: Moment {_isAMomentObject: true, _i: "2020-08-04", _f: "YYYY-MM-DD", _isUTC: false, _pf: {…}, …}
datum: "2020-08-04"

• javascript
• arrays
• sorting
• date

Share Improve this question Follow edited Aug 8, 2020 at 10:36 Oliver Borner asked Aug 8, 2020 at 10:12 Oliver BornerOliver Borner 3311 silver badge55 bronze badges 7

• I tried this to convert the array into dateobjects: let data = this.trades; data.forEach(d => { d.dateObj = moment(d.datum); }); but then i have to reduce the array by its last 30 Days, that's where i stuck at the moment. Thank you! – Oliver Borner Commented Aug 8, 2020 at 10:19
• Edit the question to give a minimal reproducible example. – jonrsharpe Commented Aug 8, 2020 at 10:19
• You don't seem to have made any attempt to filter the list, maybe read developer.mozilla/en-US/docs/Web/JavaScript/Reference/… – jonrsharpe Commented Aug 8, 2020 at 10:40
• Thank you, i will have a look into it. So you mean, i have to filter the list by date first. But how do i give it the range of 30 days? That's my question. – Oliver Borner Commented Aug 8, 2020 at 10:43
• That's not currently what's asked in the question. Read the moment docs if you want to find out how to manipulate a date. – jonrsharpe Commented Aug 8, 2020 at 10:45

 |  Show 2 more ments

3 Answers 3

Sorted by: Reset to default 5

In ECMAScript, dates in the format "YYYY-MM-DD" are parsed as UTC. When creating a date using new Date(), it is based on the local date and also has a ponent for the current time so when paring values like "30 days ago" you must normalise everything to the same datum. In this case, UTC will be the simplest.

Otherwise, you'll get errors if the code is run near the start or end of the local day due to timezone offset differences where the UTC date is behind or ahead of the local date. The time ponent also should be set to zero.

The following creates a date for n days ago, then filters the dataset and sorts it. Since the supplied data is a few months old, I've made daysAgo a parameter that is passed to the function. Also, the sort uses localCompare as it's more efficient than creating and paring Date objects, and works well with ISO 8601 formatted dates.

let data = [{
    id: "95",
    datum: "2020-03-11",
    trade: "EUR/USD BUY",
    aktion: "closed",
    pips: "10"
  },
  {
    id: "94",
    datum: "2020-06-09",
    trade: "GBP/USD BUY",
    aktion: "TP Hit",
    pips: "65"
  }, {
    id: "93",
    datum: "2020-06-08",
    trade: "NZD/USD SELL",
    aktion: "SL Hit",
    pips: "-57"
  }];
  
function getDaysAgoData(data, daysAgo) {
  // Get current date
  let t = new Date();
  // Create UTC date for daysAgo
  let d = new Date(Date.UTC(t.getFullYear(), t.getMonth(), t.getDate() - daysAgo));
  // Filter and sort data
  return data.filter(item => new Date(item.datum) >= d)
             .sort((a, b) => a.datum.localeCompare(b.datum));
}

console.log(getDaysAgoData(data, 90));

This should get you going

const list = [{
    id: "95",
    datum: "2020-03-11",
    trade: "EUR/USD BUY",
    aktion: "closed",
    pips: "10"
  },
  {
    id: "94",
    datum: "2020-06-09",
    trade: "GBP/USD BUY",
    aktion: "TP Hit",
    pips: "65"
  },
  {
    id: "93",
    datum: "2020-08-01",
    trade: "NZD/USD SELL",
    aktion: "SL Hit",
    pips: "-57"
  },
]


const currentDate = new Date();
const currentDateTime = currentDate.getTime();
const last30DaysDate = new Date(currentDate.setDate(currentDate.getDate() - 30));
const last30DaysDateTime = last30DaysDate.getTime();

const last30DaysList = list.filter(x => {
  const elementDateTime = new Date(x.datum).getTime();
  if (elementDateTime <= currentDateTime && elementDateTime > last30DaysDateTime) {
    return true;
  }
  return false
}).sort((a, b) => {
  return new Date(b.datum) - new Date(a.datum);
});

console.log(last30DaysList)

Edit: Now the array is sorted (in first version I forgot this);

let arr = [{
id: "95",
datum: "2020-03-11",
trade: "EUR/USD BUY",
aktion: "closed",
pips: "10"
},
{
id: "94",
datum: "2020-07-20",
trade: "GBP/USD BUY",
aktion: "TP Hit",
pips: "65"
},
{
id: "93",
datum: "2020-06-18",
trade: "NZD/USD SELL",
aktion: "SL Hit",
pips: "-57"
},
{
id: "92",
datum: "2020-07-15",
trade: "GBP/USD BUY",
aktion: "TP Hit",
pips: "65"
},];

const today = new Date ();
result = arr.filter(obj => {
    const date = new Date(obj.datum);
    const diffTime = Math.abs(today - date);
    const diffDays = Math.ceil(diffTime / (1000 * 60 * 60 * 24)); 
    return (diffDays <=30);
});

result.sort((a,b) => {
    a = new Date(a.datum);
  b= new Date(b.datum);
  return (a<b) ? -1 : (a>b) ? 1 : 0; 
})
console.log(result);

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