Depending on weather and temperature, not just of the air but also the soil, grass seed can be up and showing in 14 days. During dry periods the seed can just sit there until conditions improve. What helps is getting good contact of the seed with the soil. Large areas contractors would use a tractor and roller, with a small domestic lawn tamping with the back of the rake after sowing is ok.
Best time is autmn and spring.
Hi when grass seeding, it will take about 8 weeks about to start to see any results. the rain will do it good but the weather is cold at the moment. It will grow slow but round about 8 weeks.
Best time to plant is early Autumn whilst the ground is still warm enough for the seeds to germinate and there is little chance of drought to follow.
Seeds will usually germinate in 10/14 days dependent upon temperature and conditions,you should avoid walking on for a full season.
The first cut of the lawn should be very light,ideally with a pair of hand shears to prevent roots pulling out.This can be followed by a light rolling,if the ground is dry enough,this will help to spread the roots
Steve Tuckey T/A Swiftsure