How do I restrict past dates in input type Date?

Question

I am trying to restrict past dates in type="date" line 145. I made a function in line 90 till line 110 but I don't know what I did wrong. The user can still choose past dates.
https://code.sololearn.com/W5WjL9n4lN7p/?ref=app

Answer 1

<form>
<label>
Choose your preferred meeting date (required, April 1st to 20th):
<input type="date" name="meeting" min="2020-07-04" max="2020-07-18" required>
<span class="validity"></span>
</label>

<p>
<button>Submit</button>
</p>
</form>

label {
display: flex;
align-items: center;
}

span::after {
padding-left: 5px;
}

input:invalid + span::after {
content: '✖';
}

input:valid+span::after {
content: '✓';
}