I am Ashlos from Keepers Vow. If I have my time zones right then your GMT is based very early in the morning compared to the server time. If I am wrong I apologies. From that bases however I will give you Keepers Vow estimated activity levels through out the day.
For regular weekdays Keepers Vow is very active between 5:00pm - 11:00pm Server Time.
During the Weekends (Friday and Saturday) however, that time is greatly extended from 12:00pm -12:00am and up Server Time.
Like any other Kinship we do have our slow times, from my own experience this is during the week and greatly on Sundays between 2:30am - 9:00am Server Time.
From the activity levels of Keepers Vow, I'd say you could decided on your own if this fits your play time to enjoy the game. If not, I hope to see you in game and maybe get to group and play with friends.