The 7th lunar day is ruled by Surya; one may begin a journey, buy conveyances, and deal with other such things of a movable nature..
Shukla Saptami is the name for the 7th Tithi (lunar day). It's the 7th Tithi of Shuklapaksha. It's nature is Mitra Prada, which can be interpreted as "one that increases friends". It's good for following works: marriage; dance, music, singing; travelling; entering house; war, works related to elephants, jewellery making and wearing, hand works, Alankar (ornamentation). According to Muhurta Chintamani and Poorva Kalamrita Surya is Devata which rules Saptami. Brihat Samhita mentions Indra, as a ruler of this lunar day. Being Bhadra (that can be translated as "lucky") and ruled by Buddha (Mercury), the 7th Tithi of Shuklapaksha is suitable for following works or actions: marriage, Upanayana, ornament making and using, clothes; art; travelling by elephant or horses, travel, conveyance; making of roads; oil massage.