Vedāṅgas are six auxiliary disciplines of the Vedas that were developed in ancient times as the help book for the study of the Veda. There are six Vedāṅgas. Here is the Vedāṅga Jyotiṣa (Mathematical Astronomy) that was developed as a technique of time calculation to know the timings of various figurative Śrauta yajñās representing various aspects of creation and gṛhya yajñas.
यथा शिखा मयूराणां नागानां मणयो यथा।
तद्वद् वेदाङ्गशास्त्राणां गणितं मूर्धनि स्थितम्॥4॥
Like the crest of peacock and the gems of cobras stand atop their head/hood, so does the mathematical astronomy stand atop all Vedāṅga Śāstras