Here is, attached as a Rainbird file, the results of my tests to stitch periods of times together (see previous question: https://community.rainbird.ai/question/hello-learners-does-anyone-know-how-to-merge-period-of-time-together-i-d-ne--60950ec5029bbd31e9db2395).

The final relationships ("test end dates" and "test start dates"), will give the end and start dates of the merged period of times, which they inherit from the period of time given as input.