As of Tracealyzer 4.3.8 you can select and measure the time between two events exactly by shift-clicking on two data points.
Spring is here in Sweden and Tracealyzer version 4.3.8 has just been released. The new version updates the target-side recorder to work with the most recent version of FreeRTOS, v10.3, and adds two new hardware ports: Cortex-R5 and the Intel (Altera) Nios-II FPGA softcore. In addition, we have made it easier to select a time interval, both in the trace view and in various graphs, and resolved a number of stability and performance issues.
Current Tracealyzer users with a maintenance contract can update within the application or by downloading the 4.3.8 binary from percepio.com/update/.