The main purpose of this legislation is to change the federal government's fiscal year from its current schedule to a new one that aligns with the calendar year. This means that instead of starting on October 1 and ending on September 30 of the following year, the fiscal year will begin on January 1 and end on December 31. Key provisions of this legislation include the formal amendment of existing laws to reflect the new fiscal year dates. Specifically, it changes the references in the law from October 1 to January 1 and from September 30 to December 31.