Hindu Marriage:
Wedding couple take 7 Feras around the pure Agni Kund.
During all the 7 Feras, pundit ji (priest) will recite a shalok, which is like a promise from bride to groom or groom to bride.
Hindu wedding always take place during the lagan period. Lagan period is calculated by the pundit ji.
In Hindu wedding, two couple's horoscope is matched. There are supposed to be 36 guun's and if all 36 match that is considered to be perfect match. Usually more than 20-22 is considered to be goof enuff.
Sikh Marriage:
Wedding couple takes 4 Lavan around the Shri Guru Granth Sahib. These Lavan were written by 4th Guru RamDass Ji.
Each time wedding couple take one round of Guru Granth Sahib ji, the Bhai Sahib will recite one lava. Each lavan is praising the Lord and basically asks couple to be in love with that universal Lord and live life according to te the Sikhi Maryada. (I am not exactly sure about the wording and meaning of all the 4 Lavan).
There is no lagan or muhurat time. Anyday in the Presence of SGGS is fine. No horoscope matching is done for the couple. But some so called Sikhs do match Horoscopes and also takes lagan/muhurat time
Sikh marriage is also called as Anand Karaj.