Diaries in Six Month Blocks

Last week I attempted to buy a new diary for the Australian financial year (July 2013 to June 2014). However, these were not yet in stock and the calendar year diaries (January to December 2013) were being sold off cheap. My diary has a reusable Planner Cover, with a replaceable Planner Refill. So perhaps what is needed are two refills: one for each six months. That way a calendar year diary (January to December Planner Refill) or financial year diary (January to December Planner Refill) could be constructed from the cover and two refills. Diaries would be more up to date and the retailer's stock would not expire as often.