I seen my profile at morning the total activity was 70, and suddenly at night the activity was changed to 84,
after one day,
I seen my profile in next morning the total activity was changed from 84(at night) to 70, and now in night the activity changed from 70 to 84.
is it a bug ? is it happening with other members?
https://ibb.co/nDDmLxmThis is why you need to read stickies on Beginners & Help Section before posting in the forum. This thread
https://bitcointalk.org/index.php?topic=1689727.0 explains everything about your uncertainty and you should read it thoroughly as future reference in case you encounter this kind of issue in the future.
***Quote from Lauda PostHow is forum activity calculated?Activity is calculated with the following formula:
activity = min(time * 14, posts)
Activity is increased by posting and is updated every hour; however, the updated number of activity points will be reflected at your profile at the end of the current
activity period. As a note, in case you have latent activity points from earlier periods (meaning activity periods where you didn't post daily: in this case, the days when you did not post become latent activity points), these ones will be updated on your profile after 1 hour. You can gain a maximum of 14 activity points every 2 weeks.