bade hi aaram se, Darshan ke liye 1 din hi kafi hai, aap subah Jammu se katra ja sakte hain 2.5 hr max mein(Using Bus, Taxi takes 1.5 hours), then you can complete your journey to Bhawan to and fro in about 8 hours on foot(assuming you are a brisk walker and I have taken 2 hours buffer for Darshan Queue). This way you will be back in katra on same night.