revision:
The step attribute specifies the legal number intervals for an <input> element.The step attribute can be used on the <input> element.
Example: if step="3", legal numbers could be -3, 0, 3, 6, etc.
The step attribute can be used together with the "max" and "min" attributes to create a range of legal values.
The step attribute works with the following <input> types: "number", "range", "date", "datetime", "datetime-local", "month", "time" and "week".
<input type=" " step="number">
input type:date; value=1 (day); example: <input type="date" min="2019-12-25" step="1">
input type:month; value=1 (month); example:<input type="month" min="2019-12" step="12">
input type:week; value=1 (week); example:<input type="week" min="2019-W23" step="2"
input type:time; value=60 (seconds); example:<input type="time" min="09:00" step="900">
input type:datetime-local; value=1 (day); example:<input type="datetime-local" min="019-12-25T19:30" step="7">
input type:number; value=1; example:<input type="number" min="0" step="0.1" max="10">
input type:range; value=1; example:<input type="range" min="0" step="2" max="10">
<form style="margin-left:3vw;" action="/action_page.php">
<label for="points">Points:</label>
<input type="number" id="points" name="points" step="3">
<input type="submit">
</form>
<input style="margin-left:3vw;" type="date" min="2019-12-25" step="1"><br><br>
<input style="margin-left:3vw;" type="month" min="2019-12" step="12"><br><br>
<input style="margin-left:3vw;" type="week" min="2019-W23" step="2"><br><br>
<input style="margin-left:3vw;" type="time" min="09:00" step="900"><br><br>
<input style="margin-left:3vw;" type="datetime-local" min="019-12-25T19:30" step="7"><br><br>
<input style="margin-left:3vw;" type="number" min="0" step="0.1" max="10"><br><br>
<input style="margin-left:3vw;" type="range" min="0" step="2" max="10">