The European semester is an ex ante coordination cycle of economical and budgetary policies of EU member states. This cycle covers the 6 first months of the calendar during which budgetary (stabilitily programme) and structural (national reform plan) policies are first prepared at national level and then assessed at European level (by the Commission, Eurogroup/Ecofin….).
Later in the year, member states are required to submit before 15 October a "draft budgetary plan" for the following year, which is then assessed by the European Commission.
The "European semester" cycle is illustrated in the chart below.