Good afternoon everyone! I need a function that I enter a date and it returns me the date of the last four months, can be done in angular js or javascript, can you give me some help with this?
I want to get the last four months / year of a date for example
"Fri Sep 22 2017 14:42:35 GMT-0300"
and the output example
"Fri Sep 22 2017 14:42:35 GMT-0300",
"Fri Out 22 2017 14:42:35 GMT-0300",
"Fri Nov 22 2017 14:42:35 GMT-0300",
"Fri Dez 22 2017 14:42:35 GMT-0300"
Suggestion JavaScript :
function foobar( dt )
{
var array = [];
var d = new Date( dt );
for( var i = 0; i < 4; i++ )
{
var m = d.getMonth();
d.setMonth( m - 1 );
if( d.getMonth() != m - 1 && (d.getMonth() != 11 || (m == 11 && d.getDate() == 1)))
d.setDate(0);
array[i] = new Date(d);
}
return array;
}
Testing with HTML :
<html>
<head>
<script>
function foobar( dt )
{
var array = [];
var d = new Date( dt );
for( var i = 0; i < 4; i++ )
{
var m = d.getMonth();
d.setMonth( m - 1 );
if( d.getMonth() != m - 1 && (d.getMonth() != 11 || (m == 11 && d.getDate() == 1)))
d.setDate(0);
array[i] = new Date(d);
}
return array;
}
</script>
</head>
<body>
<script>
var d = foobar( 'Sep 22 2017' );
for(i = 0; i < 4; i++ )
window.document.write( d[i] + '<BR>' );
window.document.write( '<BR>' );
var d = foobar( 'Apr 30 2017' );
for(i = 0; i < 4; i++ )
window.document.write( d[i] + '<BR>' );
window.document.write( '<BR>' );
var d = foobar( 'Oct 31 2017' );
for(i = 0; i < 4; i++ )
window.document.write( d[i] + '<BR>' );
</script>
</body>
</html>
Output:
Tue Aug 22 2017 00:00:00 GMT-0300
Sat Jul 22 2017 00:00:00 GMT-0300
Thu Jun 22 2017 00:00:00 GMT-0300
Mon May 22 2017 00:00:00 GMT-0300
Thu Mar 30 2017 00:00:00 GMT-0300
Tue Feb 28 2017 00:00:00 GMT-0300
Sat Jan 28 2017 00:00:00 GMT-0200
Wed Dec 28 2016 00:00:00 GMT-0200
Sat Sep 30 2017 00:00:00 GMT-0300
Wed Aug 30 2017 00:00:00 GMT-0300
Sun Jul 30 2017 00:00:00 GMT-0300
Fri Jun 30 2017 00:00:00 GMT-0300
To generate the date of the day in the last four months:
function mesAnterior(date, diff) {
const d = new Date(date);
d.setMonth(d.getMonth() + diff);
return d;
}
function dataNosUltimosQuatroMeses(data) {
const datas = [];
for (let i = 1; i < 5; i++) {
datas.push(mesAnterior(data, i * -1));
}
return datas;
}
const hoje = new Date();
console.log(dataNosUltimosQuatroMeses(hoje)); If you want the next / future 4 months, just change i * -1 to i * 1
I understand that you want to display the exact date (s) every X months ago, see if it caters to you:
function exibeData(){
var dataPreenchida = document.getElementById("Data").value;
var qtd = document.getElementById("Quantidade").value;
if(dataPreenchida){
while(qtd>0){
console.log(subtraiMes(dataPreenchida, qtd));
qtd--;
}
}
}
function subtraiMes(str, qtd){
var d = new Date(str);
d.setMonth( d.getMonth( ) - qtd );
return d;
}<div>
<p>Preencha a data</p>
<input type="date" name="Data" id="Data" />
</div>
<div>
<p>Quantidade de meses atrás</p>
<select name="Quantidade" id="Quantidade">
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4" selected="selected">4</option>
<option value="5">5</option>
<option value="6">6</option>
<option value="7">7</option>
<option value="8">8</option>
<option value="9">9</option>
<option value="10">10</option>
<option value="11">11</option>
<option value="12">12</option>
</select>
</div>
<div>
<button type="button" onclick="exibeData();">
Exibe data
</button>
</div>