How to make a Rust time command plugin (/time chat command)

using System;
using System.Collections.Generic;
using Newtonsoft.Json;
using Oxide.Core;
using UnityEngine;

namespace Oxide.Plugins
{
    [Info("Time Command", "RustPluginGenerator", "1.0.0")]
    [Description("Adds a /time chat command that reports the in-game time, real server time and the countdown to sunrise or sunset.")]
    public class TimeCommand : RustPlugin
    {
        private const string PermUse = "timecommand.use";

        private PluginConfig config;

        private class PluginConfig
        {
            [JsonProperty("Sunrise hour (0-23)")]
            public int SunriseHour = 6;

            [JsonProperty("Sunset hour (0-23)")]
            public int SunsetHour = 20;
        }

        protected override void LoadDefaultConfig() => config = new PluginConfig();

        protected override void LoadConfig()
        {
            base.LoadConfig();
            try
            {
                config = Config.ReadObject<PluginConfig>();
                if (config == null) throw new Exception();
            }
            catch
            {
                PrintWarning("Configuration file is invalid, using defaults");
                LoadDefaultConfig();
            }
            SaveConfig();
        }

        protected override void SaveConfig() => Config.WriteObject(config);

        protected override void LoadDefaultMessages()
        {
            lang.RegisterMessages(new Dictionary<string, string>
            {
                ["Reply"] = "In-game time: {0} | UTC: {1} | Next {2} in {3} ({4})",
                ["Sunrise"] = "sunrise",
                ["Sunset"] = "sunset",
                ["NoPermission"] = "You do not have permission to use this command.",
                ["Unavailable"] = "The server clock is unavailable right now."
            }, this);
        }

        private string Msg(string key, string userId = null, params object[] args) =>
            string.Format(lang.GetMessage(key, this, userId), args);

        private void Init()
        {
            permission.RegisterPermission(PermUse, this);
        }

        [ChatCommand("time")]
        private void CmdTime(BasePlayer player, string command, string[] args)
        {
            if (player == null) return;
            if (!permission.UserHasPermission(player.UserIDString, PermUse))
            {
                SendReply(player, Msg("NoPermission", player.UserIDString));
                return;
            }

            float timeOfDay;
            float dayLength;
            if (!TryReadClock(out timeOfDay, out dayLength))
            {
                SendReply(player, Msg("Unavailable", player.UserIDString));
                return;
            }

            int sunrise = Mathf.Clamp(config.SunriseHour, 0, 23);
            int sunset = Mathf.Clamp(config.SunsetHour, 0, 23);

            bool countingToSunrise = timeOfDay >= sunset || timeOfDay < sunrise;
            int targetHour = countingToSunrise ? sunrise : sunset;
            string label = Msg(countingToSunrise ? "Sunrise" : "Sunset", player.UserIDString);

            float hoursAhead = targetHour - timeOfDay;
            if (hoursAhead < 0f) hoursAhead += 24f;
            if (hoursAhead > 24f) hoursAhead -= 24f;

            int minutesAhead = Mathf.RoundToInt(hoursAhead / 24f * dayLength);

            string inGame = FormatHour(timeOfDay);
            string realTime = DateTime.UtcNow.ToString("HH:mm") + " UTC";
            string target = FormatHour(targetHour);

            SendReply(player, Msg("Reply", player.UserIDString, inGame, realTime, label, FormatMinutes(minutesAhead), target));
        }

        private bool TryReadClock(out float timeOfDay, out float dayLength)
        {
            timeOfDay = 0f;
            dayLength = 45f;

            string timeValue = ConsoleSystem.Run(ConsoleSystem.Option.Server.Quiet(), "env.time");
            if (string.IsNullOrEmpty(timeValue) || !float.TryParse(timeValue, out timeOfDay))
                return false;

            string lengthValue = ConsoleSystem.Run(ConsoleSystem.Option.Server.Quiet(), "env.daylength");
            float parsedLength;
            if (!string.IsNullOrEmpty(lengthValue) && float.TryParse(lengthValue, out parsedLength) && parsedLength > 0f)
                dayLength = parsedLength;

            timeOfDay %= 24f;
            if (timeOfDay < 0f) timeOfDay += 24f;
            return true;
        }

        private static string FormatHour(float hour)
        {
            int total = Mathf.RoundToInt(hour * 60f) % (24 * 60);
            if (total < 0) total += 24 * 60;
            return string.Format("{0:00}:{1:00}", total / 60, total % 60);
        }

        private static string FormatMinutes(int minutes)
        {
            if (minutes <= 0) return "under a minute";
            int h = minutes / 60;
            int m = minutes % 60;
            if (h == 0) return m + "m";
            return h + "h " + m + "m";
        }
    }
}