//When player becomes a VIP:
    VIP[playerid] = (gettime() + ConvertToSeconds());

//At the bottom of your script:
stock ConvertToSeconds(years = 0, months = 0, days = 0, hours = 0, minutes = 0, seconds = 0)
{
    new time = 0;
    time += (years * 31536000); //Assumptions that each year is 365 days.
    time += (months * 2592000); //Assumptions that each month is 30 days.
    time += (days * 86400);
    time += (hours * 3600);
    time += (minutes * 60);
    time += seconds;
    return time;
}

VIP[playerid] = (gettime() + ConvertToSeconds(.months = 3, .days = 23, .hours = 14, .seconds = 12));

public OnGameModeInit()
{
    SetTimer("CheckVIP", 60000, true);
    return 1;
}

forward CheckVIP();
public CheckVIP()
{
    for(new i = 0; i < MAX_PLAYERS; i++) //foreach is the better option
    {
        if(!IsPlayerConnected(i)) continue;
        if(!VIP[i]) continue;
        if(VIP[i] <= gettime())
        {
            VIP[i] = 0;
            SendClientMessage(i, -1, "Your VIP has expired.");
        }
    }
    return 1;
}

INI_WriteInt(File, "DonateRank", PlayerInfo[playerid][pDonateRank]);
INI_WriteInt(File, "VIPInviteDay", PlayerInfo[playerid][pVIPInviteDay]);
INI_WriteInt(File, "TempVIP", PlayerInfo[playerid][pTempVIP]);

DonateRank = 3
VIPInviteDay = 0
TempVIP = 200754

CMD:setvip(playerid, params[])
{
	if(PlayerInfo[playerid][pAdmin] >= 99999 || PlayerInfo[playerid][pShopTech] >= 1)
	{
		new string[128], giveplayerid, level, days, hours;
		if(sscanf(params, "uddd", giveplayerid, level, days, hours))
		{
			SendClientMessageEx(playerid, COLOR_WHITE, "USAGE: /setvip [playerid] [level] [days] [hours]");
			SendClientMessageEx(playerid, COLOR_GRAD3, "Available Levels: |0| None |1| Bronze |2| Silver |3| Gold |4| Platinum |5| Moderator");
			return 1;
		}
		if(IsPlayerConnected(giveplayerid))
		{
			if(giveplayerid != INVALID_PLAYER_ID)
			{
				if(level < 0 || level > 5) return SendClientMessageEx(playerid, COLOR_GRAD1, "VIP Level can not be below 0 or above 6.");
				if(days < 0 || days > 30) return SendClientMessageEx(playerid, COLOR_GREY, "VIP Days can't be bigger than 30 days.");
				if(hours < 0 || hours > 24) return SendClientMessageEx(playerid, COLOR_GREY, "VIP Hours can't be bigger than 24 hours.");
				new daycal = 86400*days;
				new hourcal = 3600*hours;
				new viptime = daycal+hourcal;
				
				PlayerInfo[giveplayerid][pDonateRank] = level;
				PlayerInfo[giveplayerid][pTempVIP] = viptime;
				PlayerInfo[giveplayerid][pBuddyInvited] = 1;

PlayerVIP[playerid] = gettime()+60*8400;
/*
PlayerVIP[playerid] is the player variable.
60 being the amount of days.
*86400 times it. Basically sets an expiry some time in the future, and yes, this will decrease even when the server is offline since gettime() uses UNIX timestamps. 

*/

IniWriteInt(somefile,"VIP",PlayerVIP[playerid]);

//checking if they're VIP still:

if(PlayerVIP[playerid] > gettime())
{
    //they are
}
else
{
    //they arent.
}

if(sscanf(params, "uddd", giveplayerid, level, days, hours))

new daycal = 86400*days;
new hourcal = 3600*hours;
new viptime = daycal+hourcal;

PlayerInfo[giveplayerid][pTempVIP] = gettime() + viptime;

new File: File = INI_Open("user.ini");
INI_WriteInt(File, "TempVIP", PlayerInfo[playerid][pTempVIP]);

public OnGameModeInit()
{
    SetTimer("CheckVIP", 60000, true);
    return 1;
}

CMD:setvip(playerid, params[])
{
    if(PlayerInfo[playerid][pAdmin] < 99999 && !PlayerInfo[playerid][pShopTech]) return SendClientMessage(playerid, -1, "You are not authorised to use this command.");
    new giveplayerid, level, days, hours;
    if(sscanf(params, "uddd", giveplayerid, level, days, hours))
        return SendClientMessageEx(playerid, COLOR_WHITE, "USAGE: /setvip [playerid] [level] [days] [hours]") &&
        SendClientMessageEx(playerid, COLOR_GRAD3, "Available Levels: |0| None |1| Bronze |2| Silver |3| Gold |4| Platinum |5| Moderator");
    if(!IsPlayerConnected(giveplayerid) || giveplayerid == INVALID_PLAYER_ID) return SendClientMessage(playerid, -1, "Player is not connected.");
    if(!(0 <= level <= 5)) return SendClientMessageEx(playerid, COLOR_GRAD1, "VIP Level can not be below 0 or above 5.");
    if(!(0 <= days <= 30)) return SendClientMessageEx(playerid, COLOR_GREY, "VIP Days can't be bigger than 30 days.");
    if(!(0 <= hours <= 23)) return SendClientMessageEx(playerid, COLOR_GREY, "VIP Hours can't be bigger than 23 hours.");
    new string[128], viptime = (gettime() + ConvertToSeconds(.days = days, .hours = hours));
    PlayerInfo[giveplayerid][pDonateRank] = level;
    PlayerInfo[giveplayerid][pTempVIP] = viptime;
    PlayerInfo[giveplayerid][pBuddyInvited] = 1;
    new INI:File = INI_Open("user.ini");
    INI_SetTag(File, "data");
    INI_WriteInt(File, "TempVIP", PlayerInfo[giveplayerid][pTempVIP]);
    INI_WriteInt(File, "DonateRank", PlayerInfo[giveplayerid][pDonateRank]);
    INI_Close(File);
    new rank[15];
    switch(level)
    {
        case 0: rank = "Normal Player";
        case 1: rank = "Bronze VIP";
        case 2: rank = "Silver VIP";
        case 3: rank = "Gold VIP";
        case 4: rank = "Platinum VIP";
        case 5: rank = "Moderator";
    }
    format(string, sizeof(string), "You have been given a %s status.", rank);
    SendClientMessage(giveplayerid, -1, string);
    format(string, sizeof(string), "You have given a %s status.", rank);
    SendClientMessage(playerid, -1, string);
    return 1;
}

forward CheckVIP();
public CheckVIP()
{
    for(new i = 0; i < MAX_PLAYERS; i++) //foreach is the better option
    {
        if(!IsPlayerConnected(i)) continue;
        if(!PlayerInfo[i][pTempVIP]) continue;
        if(PlayerInfo[i][pTempVIP] <= gettime())
        {
            PlayerInfo[i][pTempVIP] = 0;
            PlayerInfo[i][pDonateRank] = 0;
            SendClientMessage(i, -1, "Your VIP has expired.");
        }
    }
    return 1;
}

stock ConvertToSeconds(years = 0, months = 0, days = 0, hours = 0, minutes = 0, seconds = 0)
{
    new time = 0;
    time += (years * 31536000); //Assumptions that each year is 365 days.
    time += (months * 2592000); //Assumptions that each month is 30 days.
    time += (days * 86400);
    time += (hours * 3600);
    time += (minutes * 60);
    time += seconds;
    return time;
}

stock ConvertToDaysAndHours(days = 0, hours = 0, minutes = 0, seconds = 0)
{
    while(seconds >= 60) minutes++, seconds -= 60;
    while(minutes >= 60) hours++, minutes -= 60;
    while(hours >= 24) days++, hours -= 24;
    new string[55], fstr[20];
    if(days) format(fstr, sizeof(fstr), (hours || minutes || seconds) ? ("%d days, ") : ("%d days"), days), strins(string, fstr, 0);
    if(hours) format(fstr, sizeof(fstr), (minutes || seconds) ? ("%d hours, ") : ("%d hours"), hours), strins(string, fstr, strlen(string));
    if(minutes) format(fstr, sizeof(fstr), (seconds) ? ("%d minutes, ") : ("%d minutes"), minutes), strins(string, fstr, strlen(string));
    if(seconds) format(fstr, sizeof(fstr), "%d seconds", seconds), strins(string, fstr, strlen(string));
    return string;
}

forward LoadDonator_data(playerid, name[], value[]);
public LoadDonator_data(playerid, name[], value[])
{
    INI_Int("TempVIP", PlayerInfo[playerid][pTempVIP]);
    INI_Int("DonateRank", PlayerInfo[playerid][pDonateRank]);
    return 1;
}

//When user logs in:
INI_ParseFile("user.ini", "LoadDonator_%s", .bExtra = true, .extra = playerid);