You do not always know the timing of contract-related events (installation, acceptance by customer, and so on) in advance when you create a service contract. For this reason, it is possible for the system to indirectly determine dates based on rules you specify in Customizing for Sales.

The following graphic shows examples of date determination rules:

In the examples above, the rules determine the following dates:

• The start date of a contract is the date on which the product is installed at the customer site.
• The end date is the installation date plus one year.

When you create the contract, you leave the start and end dates blank. Later, when you enter the installation date in the contract, the system is able to automatically determine the validity period using the baseline date (the installation date) and the date determination rules.

The following figure illustrates the example:

The following dates can be used as baseline dates:

• Current date
• Start date
• End date
• Billing date
• Start date plus contract duration
• Installation date
• Assembly date
• Acceptance date (date the customer officially accepts the installation)
• Date on which contract is signed