If you sign up for a Stryd training plan, you can select which day you typically do a long run (Saturday or Sunday). You can currently not control on which days workout appear on your calendar. Some suggestions:
1. After adding the plan to your calendar you can then move scheduled runs as needed (https://support.stryd.com/hc/articles/360055659794)
2. To customize a training plan within the Stryd ecosystem, consider the Stryd membership feature tool: Stryd's Training Plan Builder
3. If you execute a run on a different day, you can still select that workout on your Garmin or Apple Watch. In PowerCenter, you can associate a workout with an executed run on a different day.
4. If you set up a training plan in TrainingPeaks, FinalSurge or 2PEAK you have complete flexibility.