Not quite right prayer times for Indonesia/Jakarta

[bayazidbh]

Describe the bug
Assalamualaikum akhi/ukhti, thank you for the app, I highly appreciated the existence of an open-source Adzan app due to my concerns with Muslim Pro data collection practices. However, I have a concern:

The prayer times for Indonesia seems a bit off. The times from Muslim Pro (below in screenshot) seems a bit closer to what the local mosque accepts (for this day, it is: Fajr/Subuh at 04:43, Syuruq at 05:59, Dzuhur at 12:02, Asr at 15:21, Maghrib at 17:56, Isya at 19:08).

The accuracy varies out of the year, of course, but Al-Azan has more often been both earlier and marginally less accurate than Muslim Pro.

To Reproduce
Set Lat to -6.2411196 and Long to 106.8573645, check between Al-Azan, Muslim Pro, and official Kemenag times.

Expected behavior
Err on being a bit later on most of them, particularly for Maghrib for peace of mind when breaking fast, or otherwise in lockstep with Kemenag times for the district.

Screenshots

Device Info:

• Device: Samsung A55 5G
• OS: Android 14, One UI 6.1

App Version:
F-Droid: No (GitHub version, Version 1.17.10-rc 20240809)

Additional context
A few things I'd like to suggest:

1. Perhaps a per country Automatic Settings could be made? To make the process easier, perhaps you can allow users to send their adjustments/advanced settings data to you (opt-in ofc). Perhaps as a sharable profile a la Steam controller profiles.
2. There should be a warning to users to double check with their official local adzan times.
3. A batch adjustment box would be useful- as you can see from the second Muslim Pro screenshot, it's mostly 2 minutes early, so I could just +2 on everything and then +1/-4 for the one thing. My main concern is doing prayers/iftar before it is time, especially since people often ask me for Iftar time.

Thank you for your time and effort regardless, wassalamualaikum warahmatullahi wabarakatuh.

Edit:

It seems that following Muslim Pro manual correction of 2,-2,3,2,2,2 worked, so that makes me wonder how they found their correction.

[meypod]

Wa alaykum assalam

First thing I would do when comparing times is to make sure you have the same coordinates. it's usually the main cause for getting different times

then if the accuracy varies throughout the year (like if there's 1 minute error then 5 minutes error another time) , it's either a different calculation angle, or with different parameters
and lastly there can be some calculation or rounding error when everything else is not the cause
sometimes some methods, like diyanet of turkey, have special rules or calculation settings that makes it hard for apps/calculators to follow, and need you to access their times through internet (which al-azan does not do)

about suggestions:

1. I'm not sure and it's really hard to gather correct information about this. and I'm removing the internet connection when I rewrite the app, and having servers for those data has costs which I'm not willing to pay.
2. I thought the default message above the methods was enough to trigger users' attention to double check the times without scaring them off. I'll note this when I'm rewriting the app.
3. I get it, but currently I'm not adding new features to the app, simply because I plan to rewrite the app with a new design from scratch, and I can't put much time on this project at the time.

[bayazidbh]

Thank you for your replies. Understandable about removing internet connection, especially for FOSS project. Though, for the point about server, there is the option of hosting on GitHub a la Tachiyomi repos.

I don't think I noticed any warning. I think an entire page with proper explanation and "I Understand" checkbox that USER is the one that's supposed to adjust the times would be very good, yes. In addition, the adjustment page should be more prominent in that case.