Have you tested and confirmed it has been running slow for 20seconds/day for at least a week or more?? That would mean more than 2 mins slow per week.

May i know what model is it so that we can have a check on the movement it uses??

FYI, even a chronometer (COSC certified movement) has an accuracy of +6 / -4 seconds per day. So if for your case, it slows for 7 seconds after one whole day, it doesnt seem that bad enough for me. 

I asked before in watchforum, it seems that that 7 sec slower is still ok. How long have you been using your watch? However I’m not so sure of Japanese movement but my Tissot is giving me constant 3 secs slow per 24 hours.

I keep track of it by comparing it with my phone (just like you did) every day at 7am, 3pm and 11pm. I have already gathered 7 days of data to do this analysis.

Maybe you can also do the same and monitor it for 1 week, and wear it everyday to make sure the power reserve is sufficient (more than half) before deciding whether to bring it to service Centre or not ?

20 seconds slow per day is really horrible   

Since you owned this watch for 4 months, and have been wearing it for quite some time, i think it is better to bring your watch back to the service provider and have them regulate it for you. 

BTW, while waiting for the time to send in your watch, you can also try to position your watch differently every night. For eg:

1) horizontal with dial facing up
2) horizontal with dial facing down
3) vertical with crown facing up
4) vertical with 3 facing up (crown down)
5) vertical with 12 up (crown at the right)
6) vertical with 6 up (crown at the left)

and see if it makes any difference?? From what i have read, different position might actually making the watch either gain or lose time.

As in my case, i like to wear my watch on my right wrist, and so, most of my time the watch is at a position where the crown is facing up. Since i am also still new to this automatic watch, i will continue to try and update here from time to time.

Thanks for sharing, that link is super useful!

But are you satisfied of your watch being slow constantly at 20seconds per 24 hours ??

P/s to update, my watch just lost 0.5 seconds in 24 hours since yesterday! Wow! And I let it in the crown up position when I Went to bed. Will try another position tonight

Bro, my friend Seiko 5 (which he bought for around rm500) is keeping quite good time according to him, at only +- 10 seconds per day

Just to update, it has just run fast for the first ever time of me owning this watch (+1 sec per day)

P/s mechanical watch is really a magnificent invention

Mind sharing the name of the shop so that all of us here be aware of it ?