Salesforce Derived Fields: Definition, Value Calculation, and Timestamp Impact

How Derived Field Values Are Calculated

Derived fields are treated as formula fields and their values are calculated when queried — they are never actually stored. Because the value is not stored, the record is not modified by a user or the system, and no update or modification of the record takes place.

Examples of Derived Fields

• The Status field on the Entitlement object is derived from the Start Date and End Date of the associated record. If the fields are updated manually, the Status changes to Active or Inactive and timestamps are updated. However, if there is no manual change and the End Date has passed, the Status becomes "Expired" — this value is set at query time and never stored.
• The isViolated field on the Milestone object is derived from the Completion Date and Target Date. See this related article for a complete explanation.
• For any custom formula field where the formula compares the current DateTime to another DateTime, the formula field changes value despite no record updates occurring, no triggers firing, and no timestamps being changed.

Impact on SystemModStamp and LastModifiedDate

Because derived field values are calculated at query time and never stored, no DML (Data Manipulation Language) operation occurs when their value changes. This means:

• The SystemModStamp timestamp on the record is not updated
• The LastModifiedDate is not updated
• No triggers or automations fire as a result of a derived field value change