This question concerns in particular the case of termination of an employment contract before the inception of implementation. Termination of a duly established employment contract, even before the inception of implementation, may give rise to the right to notice and damages.
Apart from the case of termination of an employment contract before the inception of implementation, it must be recognised that the clauses of the contract only take effect from the effective date of the contract as indicated in the contract and not from the moment of signing the employment contract, unless those two dates coincide.
Examples
If the employment contract was signed in June 2010 and a salary (e.g. € 3,000) was agreed between the parties, but without reference to the index, and in July 2010 an indexation of salaries took place and the start of work has been fixed for the month of August of the same year, the salary determined in the employment contract would not have to be adapted to the variations in the cost of living (indexation) taking place in month of July. To avoid any problem, it is advisable to indicate the index in the employment contract.