You can add an expire field. You can use this command and modify it to your needs. You will have to restrict it to ONLY being able to create pets and if you want a static number of '90' days = 3 months, you will have to set that in the "long expiry" field in the command below.
PHP Code:
} else if (sub[0].equalsIgnoreCase("expiringitem")) {
MapleItemInformationProvider ii = MapleItemInformationProvider.getInstance();
if (sub.length < 2) {
return false;
}
int item;
long days = Integer.parseInt(sub[2]);
long expiry = System.currentTimeMillis() + (days * 24 * 60 * 60 * 1000);
try {
item = Integer.parseInt(sub[1]);
} catch (NumberFormatException e) {
c.getPlayer().oakMessage("Error while making item.");
e.printStackTrace();
return false;
}
if (ii.getInventoryType(item).equals(MapleInventoryType.ETC)) {
c.getPlayer().dropMessage(1, "You can't create ETCs with this command.");
return false;
}
if (ii.getInventoryType(item).equals(MapleInventoryType.EQUIP)) {
MapleInventoryManipulator.addById(c, item, (short) 1, "", expiry);
} else if (!ii.itemExists(item)) {
c.getPlayer().dropMessage(5, item + " does not exist.");
} else {
MapleInventoryManipulator.addById(c, item, (short) 1, expiry);
}