[Nexus]

Я бы так сделал:

<textarea style="width:100%;min-height:100px;" id="result">/*!
 * box-shadows.min.css v1.0.1g#DAY#MONTH#HOURS#MONUTES - https://github.com/madeas/box-shadows.css
 * 
 * Copyright (c) 2018 Andrej Sharapov
 * Licensed under MIT (https://github.com/madeas/box-shadows.css/blob/master/LICENSE)
 */
</textarea>
<script>
const date=new Date();
result.value=result.value
	.replace('#DAY',date.getDate())
	.replace('#MONTH',date.getMonth()+1)
	.replace('#HOURS',date.getHours())
	.replace('#MONUTES',date.getMinutes());
</script>