One Workbook for one accounting period data

1. Use one workbook (file) for only one accounting period. For example, file name AccJanDec2011.xls contains data for acounting period 1 January to 31 December 2011.

2. Why ? (1) Too many data and formulas will slow down calculations. (2) Better files organization.

3. Though usually one accounting period (12 months) equal to one accounting year (12 months), but in some cases, one accounting period may span over two years eg 1 July 2010 to 30 June 2011 (12 months).