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Display current week in react-native

I need to display the current week of the month in the following format in react-native:
(Week 2: 05.10 - 11.10) (example of week 2 of current month)
What would be some suggestions as how to achieve this? I know that there are packages such as momentjs to build this but would like some examples of how to achieve this
any help is appreciated!

You can adapt the code below. I say "adapt" because you haven't specified when your week starts (Sunday or Monday?) or how you want to count which week within the month it is (i.e. is week #1 the first full week? The code below assumes so).
Anyway, by clicking the "Run Code Snippet" button, you'll see what it does, including some intermediate steps, which are there to illustrate where the values are coming from, and therefore what you might want to "adapt" for your needs.
//get the first day of week and last day of week, borrowed from https://stackoverflow.com/a/64529257/1024832 above
const getWeek = (date = new Date()) => {
const dayIndex = date.getDay();
const diffToLastMonday = (dayIndex !== 0) ? dayIndex - 1 : 6;
const dateOfMonday = new Date(date.setDate(date.getDate() - diffToLastMonday));
const dateOfSunday = new Date(date.setDate(dateOfMonday.getDate() + 6));
return [dateOfMonday, dateOfSunday];
}
//get week number w/in the month, adapted from https://stackoverflow.com/a/57120367/1024832
const getWeekNumber = () => {
let todaysDate = moment(moment.now());
let endOfLastMonth = moment(todaysDate).startOf('month').subtract(1, 'week');
let weekOfMonth = todaysDate.diff(endOfLastMonth, 'weeks');
return weekOfMonth;
}
//capture/log some steps along the way
const [Monday, Sunday] = getWeek();
console.log("First/Last of week as Date Objects: ", Monday, Sunday);
let Monday_formatted = moment(Monday).format("DD.MM");
let Sunday_formatted = moment(Sunday).format("DD.MM");
console.log(Monday_formatted, "-", Sunday_formatted);
console.log("Week #:", getWeekNumber());
//set the DIV content
document.getElementById("datehere").innerText = `(Week ${getWeekNumber()}): ${Monday_formatted} - ${Sunday_formatted}`;
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.29.1/moment.min.js"></script>
<div id="datehere"></div>

Here's an answer as a function which returns the current week's Monday and Sunday in an array:
getWeek = (date = new Date()) => {
const dayIndex = date.getDay();
const diffToLastMonday = (dayIndex !== 0) ? dayIndex - 1 : 6;
const dateOfMonday = new Date(date.setDate(date.getDate() - diffToLastMonday));
const dateOfSunday = new Date(date.setDate(dateOfMonday.getDate() + 6));
return [dateOfMonday, dateOfSunday];
}
const [Monday, Sunday] = getWeek();
console.log(Monday, Sunday);
The response is two valid date objects. You can also pass a date object for the function to get Monday and Sunday of that date's week (e.g. getWeek(new Date(0));
But when you want to parse those dates, you should gain better knowledge of Date Object.

Javascript how to get full two year from current month?

I have question about getting full two years from the current date. So what i did id get the current month using the new date function and used the for loop to print each of the month. But, i cant really get it to work.... I will post the code that i did below. I would be really appreciate it if anyone can tell me the logic or better way of doing it.
For example: if today current date is august it store into an array from 8 / 2020 9/ 2020 ..... 12/ 2020, 1/2021 and goes to another year to 8/2022.
var d = new Date();
var year = d.getFullYear();
var dateStr;
var currentYear;
var storeMonthYear = [];
for(var i = 1; i <= 24; i++){
dateStr = d.getMonth() + i
currentYear = year;
if(dateStr > "12"){
dateStr = dateStr - 12
// currentYear = year;
// if(currentYear){
// }
storeMonthYear[i] = dateStr + "/" + (currentYear + 1);
}
else if(dateStr > "24"){
storeMonthYear[i] = dateStr + "/" + (currentYear + 1);
}
else{
storeMonthYear[i] = dateStr + "/" + currentYear;
}
storeMonthYear[i] = d.getMonth() + i
}
export const settlementPeriod = [
{
MonthYearFirstRow1: storeMonthYear[1],
MonthYearFirstRow2: storeMonthYear[2],
MonthYearFirstRow3: storeMonthYear[3],
MonthYearFirstRow4: storeMonthYear[4],
MonthYearFirstRow5: storeMonthYear[5],
MonthYearFirstRow6: storeMonthYear[6],
MonthYearFirstRow7: storeMonthYear[7],
MonthYearFirstRow8: storeMonthYear[8],
MonthYearFirstRow9: storeMonthYear[9],
MonthYearFirstRow10: storeMonthYear[10],
MonthYearFirstRow11: storeMonthYear[11],
MonthYearFirstRow12: storeMonthYear[12],
MonthYearSecondRow13: storeMonthYear[13],
MonthYearSecondRow14: storeMonthYear[14],
MonthYearSecondRow15: storeMonthYear[15],
MonthYearSecondRow16: storeMonthYear[16],
MonthYearSecondRow17: storeMonthYear[17],
MonthYearSecondRow18: storeMonthYear[18],
MonthYearSecondRow19: storeMonthYear[19],
MonthYearSecondRow20: storeMonthYear[20],
MonthYearSecondRow21: storeMonthYear[21],
MonthYearSecondRow22: storeMonthYear[22],
MonthYearSecondRow23: storeMonthYear[23],
MonthYearSecondRow24: storeMonthYear[24]
},
];

Create the date from today, get the month and year. Iterate from 0 to 24 for now till in 24 months. If month is 12 than set month to 0 and increment the year. Push the new datestring. Increment the month for the next step.
Note: Beacsue JS counts months form 0-11 you had to add for the datestring 1 for the month and make the change of year at 12 and not 13.
let date = new Date();
let year = date.getFullYear();
let month = date.getMonth();
let res=[];
for (let i=0; i<=24; i++) {
if (month===12) {
month = 0;
year++;
}
res.push(month+1 + '/' + year);
month++;
}
console.log(res);

Here you go, you get an array of strings like "8/2020","9/2020" etc from starting month to the last month including both( in total 25 months).
If you don't want to include last month just delete +1 from for loop condition.
let currentDate = new Date();
let settlementPeriod = [];
let numberOfMonths = 24;
for(let i=0;i<numberOfMonths+1;i++){
settlementPeriod.push(currentDate.getMonth()+1+"/"+currentDate.getFullYear()); //We add current date objects attributes to the array
currentDate = new Date(currentDate.setMonth(currentDate.getMonth()+1)); //Every time we add one month to it
}
console.log(settlementPeriod);

There are a couple of things that stick out in your code sample:
You're comparing strings and numbers (e.g. dateStr > "12"). This will lead to some weird bugs and is one of JS's most easily misused "features". Avoid it where possible.
You increment the year when you reach 12 months from now, rather than when you reach the next January
You're overwriting your strings with this line storeMonthYear[i] = d.getMonth() + i so your array is a bunch of numbers rather than date strings like you expect
Here's a code sample that I think does what you're expecting:
function next24Months() {
const today = new Date()
let year = today.getFullYear()
let monthIndex = today.getMonth()
let dates = []
while (dates.length < 24) {
dates.push(`${monthIndex + 1}/${year}`)
// increment the month, and if we're past December,
// we need to set the year forward and the month back
// to January
if (++monthIndex > 11) {
monthIndex = 0
year++
}
}
return dates
}
In general, when you're dealing with dates, you're probably better off using a library like Moment.js - dates/times are one of the most difficult programming concepts.

While #Ognjen 's answer is correct it's also a bit waseful if your date never escapes its function.
You don't need a new date every time:
function getPeriods(firstMonth, numPers){
var d = new Date(firstMonth.getTime()); // clone the start to leave firstMonth alone
d.setDate(1); // fix after #RobG
var pers = [];
var m;
for(var i = 0; i< numPers; i++){
m = d.getMonth();
pers.push(`${m+ 1}/${d.getFullYear()}`)
d.setMonth(m + 1); // JS dates automatically roll over. You can do this with d.setDate() as well and when you assign 28, 29, 31 or 32 the month and year roll over automatically
}
return pers;
}

Javascript: formatting a date [duplicate]

This question already has answers here:
Where can I find documentation on formatting a date in JavaScript?
(39 answers)
Closed 4 years ago.
I want to the current date/time formatted in this format:
year+'-'+month+'-'+day+' '+hour+':'+minute+':'+second+':'+milli;
Currently I'm doing it as such. Is there a more elegant approach without the use of external libraries like moment.js?
var now = new Date();
var year = now.getFullYear();
var month = now.getMonth()+1;
var day = now.getDate();
var hour = now.getHours();
var minute = now.getMinutes();
var second = now.getSeconds();
var milli = now.getMilliseconds();
if(month.toString().length == 1) {
var month = '0'+month;
}
if(day.toString().length == 1) {
var day = '0'+day;
}
if(hour.toString().length == 1) {
var hour = '0'+hour;
}
if(minute.toString().length == 1) {
var minute = '0'+minute;
}
if(second.toString().length == 1) {
var second = '0'+second;
}
if(milli.toString().length == 1) {
var milli = '0'+milli;
}
var m_session_startTime = year+'-'+month+'-'+day+' '+hour+':'+minute+':'+second+':'+milli;

Leverage template literals instead of concatenation and padStart() to fill leading zeros.
const now = new Date();
const year = now.getFullYear();
const month = String(now.getMonth() + 1).padStart(2, "0");
const day = String(now.getDate()).padStart(2, "0");
const hour = String(now.getHours()).padStart(2, "0");
const minute = String(now.getMinutes()).padStart(2, "0");
const second = String(now.getSeconds()).padStart(2, "0");
const milli = String(now.getMilliseconds()).padStart(4, "0");
const m_session_startTime = `${year}-${month}-${day} ${hour}:${minute}:${second}:${milli}`;
console.log(m_session_startTime);

You could use moment.js, it really helps you with formatting dates.
console.log(moment().format('YYYY-MMMM-DD h:mm:ss:SSS'));
<script src="https://momentjs.com/downloads/moment.min.js"></script>
This command does the job pretty well. moment() is a date object, when there are no arguments given like in this example it takes the current time but you can also use moment("2018-12-4") for specific dates.
You can then format the date according to your need,
YYYY is the full year (2018)
MMMM is the full month name (July)
(you can also use MMM for the short version of the month name)
DD is the day as a number (24)
(you can also use dddd for the full name of the day or ddd for the short name)
h is the hour as number (22)
mm is the minute as a number (23)
ss is the second as a number (as an example 22)
SSS is the millisecond as a number (example 245)

Try this?
let date = new Date();
let jsonDate = date.toJSON();
jsonDate = jsonDate.replace(/[TZ]/g, " ");
jsonDate = jsonDate.replace(/\./g, ":");
console.log(jsonDate);
> 2018-07-24 20:32:06:435
Alternatively, if you want to split the entire thing into substrings:
let date = new Date();
let jsonDate = date.toJSON();
jsonDate = jsonDate.replace(/[TZ]/g, " ");
jsonDate = jsonDate.replace(/\./g, ":");
let dateTime = jsonDate.split(" ");
let dt = dateTime[0].split("-");
let tt = dateTime[1].split(":");
let year = dt[0];
let month = dt[1];
let day = dt[2];
let hour = tt[0];
let minute = tt[1];
let second = tt[2];
let mili = tt[3];
console.log(jsonDate);
console.log(dateTime[0]);
console.log(dateTime[1]);
console.log([year, month, day, hour, minute, second, mili].join("~"));
console.log("Date: " + [year, month, day].join("-") + " Time: " + [hour, minute, second, mili].join(":"));
> 2018-07-24 21:03:05:706
> 2018-07-24
> 21:03:05:706
> 2018~07~24~21~03~05~706
> Date: 2018-07-24 Time: 21:03:05:706
As you might have noticed from this response, I work with databases. I have heavy bash, javascript, php, sql, golang background.

Use a moment.js. Great library that is designed to exactly what you would like. You can use the .format option.
var now = moment().format('YYYY-MM-DD HH:mm:ss.SSS');
$('#timeval').text(now);
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
Current Time: <br>
<a id="timeval"></a>
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.22.2/moment.min.js"></script>
https://momentjs.com/

how to get getUTCDate() with 0

how to get getUTCDate() and getUTCMonth() with 0 ?
my code is
var d = new Date();
var day = d.getUTCDate();
var month = d.getUTCMonth()+1;
var year = d.getUTCFullYear();
If Today date is 1-1-2015 than i want to day=01 instead of 1 and month=01 instead of 1;

There's no built-in shortcut for doing that. You just put a 0 in front of it if necessary:
var month = String(d.getUTCMonth());
if (month.length === 1) {
month = "0" + month;
}
Or use a date/time library like MomentJS which features formatting functions.
On modern browsers, you can also dice up the string toISOString gives you, as it's always in UTC:
var parts = d.toISOString().substring(0, 10).split("-");
var day = parts[2];
var month = parts[1];
var year = parts[0];

Showing Invalid Date in JavaScript

I created a Javascript logic to retrieve date and time from some values.
initially i did was parsed the DateTime, convert it to string, then Split the string and retrieve the Date.
Like that i retrieved the time parsed, and atlast Joined all together(new Date + new Time).
I tried to convert it to date, now when i alert it then it says invalid Date. I want to display the newly created date just like this format.
var sampDate = new Date();
alert(sampDate);
Iam no good at explaining so iam uploading my code to fiddle and here also.
Please take a look at the JSFiddle. What i was done is below. Please point out what iam doing wrong with a detailed description. Any help will be very much appreciated.
JSFIDDLE : http://jsfiddle.net/5csge/
var date = 1745488627000;
var parsedDate = new Date(parseInt(date, 10)).toString();
var splitDate = parsedDate.split(" ");
var currentMonth;
switch (splitDate[1]) {
case "Jan":
currentMonth = 1;
break;
case "Feb":
currentMonth = 2;
break;
case "Mar":
currentMonth = 3;
break;
case "Apr":
currentMonth = 4;
break;
case "May":
currentMonth = 5;
break;
case "Jun":
currentMonth = 6;
break;
case "Jul":
currentMonth = 7;
break;
case "Aug":
currentMonth = 8;
break;
case "Sep":
currentMonth = 9;
break;
case "Oct":
currentMonth = 10;
break;
case "Nov":
currentMonth = 11;
break;
case "Dec":
currentMonth = 12;
break;
}
var time = -688627000;
var parsedTime = new Date(parseInt(time, 10)).toString();
var splitTime = parsedTime.split(" ");
var convertedEndDate = new Date(splitDate[2] + "/" + currentMonth + "/" + splitDate[3] + " " + splitTime[4]);
alert(convertedEndDate);
var currentDate = new Date();
alert(currentDate);

Your issue is here:
var convertedEndDate = new Date(splitDate[2] + "/" + currentMonth +
"/" + splitDate[3] + " " + splitTime[4]);
where you assume that 24/4/2025 00:42:53 can be passed as a parameter into a Date() object. From MDN:
dateString
String value representing a date. The string should be in a format recognized by the Date.parse() method (IETF-compliant RFC 2822 timestamps and also a version of ISO8601).
This obviously isn't ISO8601 format (that would start 2025-04-24), but it also doesn't appear to be in the format of an RFC282 timestamp either. In fact, you're better off NOT translating the month name back into a number; the following appears to work perfectly, replacing the / with spaces:
var convertedEndDate = new Date(splitDate[2] + " " + splitDate[1]
+ " " + splitDate[3] + " " + splitTime[4]);

Use New Date - setFullYear() and setHours()
new Date()
setFullYear();
setHours();
DEMO UPDATED

Use date object and sets methods.
D = new Date();
D.setDay(12);
D.setMonth(2);
when you make this, the date will continue intervally after scripte is executed