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Just like any update there isn't an specific release date for each country/network
http://www.sonymobile.com/global-en/software/phones/xperia-l/
Latest available software
You may already have the latest software, depending on the date of purchase. Software updates are released at different times depending on operator and/or country. Therefore, we cannot give you an exact date for when a specific update will be available for your device.
If you can not wait for the update then you can manually update your phone to the latest firmware
How to manually update, downgrade, root 2013 Xperias
http://talk.sonymobile.com/thread/124152
If you encounter any bugs after the latest update, it is recommended to re-install the latest update
Bridge (for Mac)
Alternatives on How to backup Xperias
http://talk.sonymobile.com/thread/36355
For C2104 users there is good news that 15.3.A.1.14 is rolled out for them as well.
At the moment the following are available:
Brazil - Generic BR
India - Generic IN
LAMGeneric(b) - Generic GEL
Thailand - DTAC TH
USA - Generic US
---
This is the complete list for C2105 right now:
Belgium - Generic BE
Germany - Genericy DE
Greece - Generic GR
Indonesia - PT. Telatama artha mandari
Indonesia - PT. Sony Indonesia
Italy - Generic IT
Mena Arabic (b) - Generic MEA
Netherland - Generic NL
Phillipines - Generic PH
Russia - Generic RU
Saudi Arabia - Generic SA
Singapore - Singtel SG
Singapore - Generic SG
Taiwan - Generic TW
Taiwan - CHT TW
Thailand - Generic TH
Ukraine - Generic UA
---
So now we are awaiting for these who have the possibility to test, to report if we get rid of the annoying bugs.
I am from India with c2104. Just few mnutes ago got notification of the new 15.3.A.1.14 update on my pc companion. Hope it will wash out the bugs...
FrankVincent thanx a lot man for providing the information 
The New Update is live in India too for C2104 users.
I have enabled in the settings of the "special features" - "Power button ends the call." I use it. And so, with the release of the software 15.3.A.1.12, bug appeared. namely: After finishing a call by pressing the power button, the phone does not stop working proximity sensor. updated today at 15.3.A.1.14, but the problem has not disappeared. Take note of this bug and fix.
http://cs3-3.4pda.to/4030121.jpg
and finally remove the inscription on the freezing of the screen ...."Swipe up or down to unlock"
15.3.A.1.14 firmware is android 4.2.2 version only and confirmed for Xperia LC2105 and C2104 over both PC Companion as well as an OTA update. It is confirmed in regions like Germany, Saudi Arabia, Belgium, India, Philippines, Russia, Pakistan, Canada. As per Sony 15.3.A.1.14 firmware brings performancetweaks, camera improvement, homescreen UI refresh and other changes are under the hood.
Changelog :-
#For C2105 – Indonesia
Download C2105_15.3.A.1.14_Indonesia.ftf
15.3.A.1.14 firmware ftf is posted on below source. Flash it with flashtool
Source - http://www.xperiaguide.com/2014/01/16/xperia-l-15-3-1-14-firmware-update-rolling-camera-improved/
was also the same problem with the sensor only when a missed call. this problem can be seen decided, but that what I described above - no.
I can install the update here from The Netherlands.
Since I first check some experiences of new firmware's, I'm still on 15.0.A.2.17 
Waiting for people who can confirm this firmware is finally bug-free..
According to Sony, the most recent update (15.3.A.1.14) was released on January 16th.
My phone however, is stuck on 15.0.A.1.31 which is several updates behind the current systems.. Why am I not getting any updates?? Is something wrong?
I have checked the phone's update center, Sony PC Companion and the Sony Update Service but no matter where I check, there are no updates showing for me.
I've been checking online and a lot of people around the world are getting these updates but I'm not getting anything..
(I'm in Canada)
Same to me. Stuck at 15.3.A.0.26 ( portugal )
The updates roll out gradually, so take some time, especially if your device is network locked. I am also still waiting for the update (UK generic). Also when you check for updates via the phone is checks for OTA (over the air) updates which generally take longer to roll out. So your best bet is checking with SUS/PCC.
Seeing that your stuck on 4.1.2 is worrying, if your on a network locked device you may not get 4.2.2 (or may take more time), sim free you should of got it by now. As for the most recent update we will just have to wait. Alternatively refer here.