The ability to execute this on people as an admin from console.

viptrial <playername> <days>​

This should override all checks: is allowed, already used, and reset the end date to the days specified.

Example

Usera has 1 day left on vip_trial and maybe I want to reward them for doing something. 

viptrial usera 7

There new expiration date should be set.

Merged post

I gave it my best go, but I dont know C# or how to code plugins for oxide.

		[ConsoleCommand("viptrialadd")]
		private void ccmdTrialAdd(BasePlayer player, string command, ConsoleSystem.arg args)
		{
			if(args.length == 0)
			{
				SendReply(args, "viptrailadd <playername> <days>");
			}	
			else
			{
				object target = FindPlayer(player, args[0]);
				if (target != null && target is BasePlayer)
				{
					if(args[1] == null)
					{
						 AddUserForTrial((target as player));
					}
					else
					{
						int i = 3;
						int.TryParse(args[1], out i);
                        if (i != 0)
						{
							AddUserForTrial((target as player), (i as days));
                        }	 
					}
				}
				else
				{
					SendReply(args, "No player with that name was found.");
				}
			}
		}	    ​

Massive bump on this post!