private int readValidityPeriodInt()
	{
		// this will convert the VP to #MINUTES
		int validity = readByte();
		int minutes = 0;
		if ((validity > 0) && (validity <= 143))
		{
			// groups of 5 min
			minutes = (validity + 1) * 5;
		}
		else if ((validity > 143) && (validity <= 167))
		{
			// groups of 30 min + 12 hrs
			minutes = (12 * 60) + (validity - 143) * 30;
		}
		else if ((validity > 167) && (validity <= 196))
		{
			// days
			minutes = (validity - 166) * 24 * 60;
		}
		else if ((validity > 197) && (validity <= 255))
		{
			// weeks
			minutes = (validity - 192) * 7 * 24 * 60;
		}
		return minutes;
	}