Hello!
I've been trying to find a working Infinite Time code for Super Mario 3D Land. I have Luma3DS 9.1 (I know there is a later version but they crash the games a lot so I'm sticking with this version) and using the Rosalina cheat engine. In my searches here are the two notable codes I found:

[Make Timer countdown from 999]
D3000000 14000000
02197A40 000055DA

Though this code does work for the Action Replay plugin, it does not work for Rosalina. Now here is the second most notable code:

[Max Infinite TIme Rev02]
D3000000 00000000
00176AEC E5802018

Mind you this is for the EU version, but I tried this on the US version for fun and it had an unforeseen yet interesting effect: Instead of starting me with Infinite Time, it started me with the time to 000 and I died instantly! This leads me to think that the latter code is closer to an Infinite Time code than the former code, it just needs to change some values around, but sadly I'm not sure where to start with this. I even tried to convert the former code from AR format to GateShark format but I failed at that too. I don't suppose there is anyone out there who knows about 3DS hacking who can help me get a working Infinite Time code in GateShark format??? I would so appreciate it!

As I coyly stated before, I think I figured out how to convert AR codes to GateShark format! I played around with the following two codes here and managed to make two working GateShark codes out of them! I am still testing it out, so I will let you know if there are any problems with them:

Invincibility (Action Replay original version)
03EA8274 E3510001

Invinciblity (GateShark version I made!)
D3000000 00000000
001A8274 E3510001
D2000000 00000000

Have Flutter With Any Powerup (Action Replay original version)
03FD270C E3A00001

Have Flutter With Any Powerup (GateShark version I made!)
D3000000 00000000
002D270C E3A00001
D2000000 00000000

Thanks in advance!!!