JavaScript Get the start and end of the day in UTC

Given a date, and the task is to determine the start and end of the day of the date using JavaScript. We’re going to discuss a few methods. These are:
JavaScript setHours() Method: This method sets the hour of a date object. This method can be used to set the minutes, seconds, and milliseconds.
Syntax:
Date.setHours(hour, min, sec, millisec)
Parameters:
- hour: This parameter is required. It specifies the integer denoting the hours. Values accepted are 0-23, but other values are also allowed.
 -1 means the last hour of the previous day and 24 means the first hour of the next day.
- min: This parameter is optional. It specifies the integer representing the minutes. Values accepted are 0-59, but other values are also allowed.
 60 means the first minute of next hour and -1 means the last minute of the previous hour.
- sec: This parameter is optional. It specifies the integer representing the seconds. Values accepted are 0-59, but other values are also allowed.
 60 means the in the first second of next minute and -1 means the last second of previous minute.
- millisec: This parameter is optional. It specifies the integer representing the milliseconds. Values accepted are 0-999, but other values are also allowed.
- -1 means the last millisecond of previous second and 1000 means the first millisecond of next second.
 
JavaScript toUTCString() Method: This method converts a Date object to a string, depending on universal time.
Syntax:
Date.toUTCString()
Return Value: It returns a string, representing the UTC date and time as a string.
Example 1: This example gets the first millisecond of the day and last millisecond of the day as well using setHours() method and converting it to UTC format using stoUTCString() method.
Javascript
| let startOfDay = newDate();startOfDay.setHours(0, 0, 0, 0);let endofDay = newDate();endofDay.setHours(23, 59, 59, 999);console.log(startOfDay.toUTCString());console.log(endofDay.toUTCString()); | 
Output
Tue, 13 Jun 2023 18:30:00 GMT gfg.html:8:9 Wed, 14 Jun 2023 18:29:59 GMT
Example 2: This example gets the first millisecond of the day and last millisecond of the day but by a different approach than previous one using setHours() method and converting it to UTC format using stoUTCString() method.
Javascript
| let startOfDay = newDate();startOfDay.setHours(0, 0, 0, 0);let endofDay = newDate();endofDay.setHours(24, 0, 0, -1);console.log(startOfDay.toUTCString());console.log(endofDay.toUTCString()); | 
Output
Tue, 13 Jun 2023 18:30:00 GMT Wed, 14 Jun 2023 18:29:59 GMT
We have a complete list of JavaScript Date Objects, to check those please go through this JavaScript Date Object Complete reference article.
 
				 
					


