rabidus-test/Assets/Scripts/LeaderboardWithDateController.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;

public class LeaderboardWithDateController : LeaderboardController
{
    public int DaysShow = 30;

    protected override void Start()
    {
        base.Start();
    }

    protected override void UpdateLeaderboard()
    {
        _entries.ForEach(x => Destroy(x.gameObject));
        _entries.Clear();
        _entries = new List<LeaderboardEntry>();

        var sortedList = PlayerSetup.Instance.AllPlayers
            .Where(y => DateTime.Parse(y.DateTime)
            .AddDays(DaysShow) >= DateTime.Now)
            .OrderByDescending(x => x.Score)
            .ToList(); 

        

        for (int i = 0; i < sortedList.Count; i++)
        {
            var newEntry = Instantiate(_leaderboardEntryPrefab, _content);
            _entries.Add(newEntry);
            newEntry.Init(sortedList[i], i);
        }
    }
}