At 1Tap, we are passionate about providing solutions that unburden sole traders and in turn save precious time and maximize tax returns. That's why the dates are set according to the standard tax period for the HMRC self employment declaration - for example, 2015-2016 tax period is April the 5th.
We intend to add a feature which will allow users to customise their tax period, but until then you can export all the data in CSV export file. That way you can easily manage and rearrange your expenses by the date you like, using Excel or other software and sum the expenses that fall into your tax year.
You can do that by tapping on the 'Settings' button in the top left corner and then choosing PDF or CSV export.