Mix cucumbers, zucchini, red onion, tomatoes, black olives, basil, and thyme together in a large salad bowl.
In a separate bowl, whisk red wine vinegar, balsamic vinegar, lemon zest, lemon juice, kosher salt, sugar, and white pepper together until thoroughly combined. Pour olive oil slowly into dressing mixture, whisking to combine. Pour dressing over salad and serve.