You must agree that 1 May was the 11.00 (see any chart). Assume 21 trading days a month on average (one is 19 and others go to 22) 1 Jul- 31 Mar = 9 months x 21 days = 189 trading days 16 Apr = 11 days (Good Friday) 189+11 = 200 days I doubt this will do any good!