I think you posted in the wrong section, this one is used for people who have some little japanese texts and need someone help translating them.
You should post in this section for romhacking problems : http://www.romhacking.net/forum/index.php/board,13.0.html
but I suppose a moderator will move your message in the good section.
September 15, 2014, 01:21:12 am - (Auto Merged - Double Posts are not allowed before 7 days.)
I check a bit and here's what I understood.
Day names in the pokegear are composed of two text strings.
A first string between : "SUN / MON / THURS / WEDNES / THURS / FRI / SATUR" (0x1430-0x1453)
and then, the game add the word "DAY" from 0x1454 to get complete version of the day names.
"SUN" pointer is "3014" (0x1422)
"MON" pointer is "3414" (0x1424)
"TUES" pointer is "3814" (0x1426)
"WEDNES" pointer is "3D14" (0x1428)
"THURS" pointer is "4414" (0x142A)
"FRI" pointer is "4A14" (0x142C)
"SATUR" pointer is "4E14" (0x142E)
So there are in a pointers table, just before the text, which is the most common thing.
If you want to expand them, you'll have to find free space in the same bank (at least, if you don't use asm hack) or it depend of the name of the days you want to put. If they all have the same ending, like the english one, it'll be easier (in french, we would be screwed because they all end with "di" except "sunday" => "dimanche").
If you manage to find enough place to put the full version, you can always erase the word "DAY" to get rid of it.
"DAY" pointer is "5414" (0x141B"). If you modify it and make it point a "50" (end dialog) somewhere in the rom, it won't be displayed (I just tried and it works). Removing it give you 4 more hex/letters for the other day names.
It don't seem to be used elsewhere because erasing it don't affect the day names in other screens.
I had found some free space at 0xFA40 but it seems to far for the pointers because it display nothing if you use that free space, so it'll be required to find some free space not to far of the other texts. I found some free space at 0x2E17-0x2E24 which works for the day names, but not sure if those "00" are unused or not. You can still try and if later in the game, you get a crash/bug, you can always reverse them back to "00" to see if it fixed the problem.
If those "00" can't be used, there are also some at 0x3FEF-0x3FFE which works too.
Either way, don't forget to put a "50" after the day names if you put some in those free space.
Hope it'll help you