Sarawak has an immigration that is separate from the rest of Malaysia so whenever you arrive from anywhere other then another city I Sarawak, you get a stamp in your passport.
While most people whom I’ve talked to got 90 days in Sarawak, regardless of how long they were in the rest of Malaysia, I only got the the duration of my time left on my first Malaysian visa (8 days).
I don’t know if this is new policy. Immigration said it was up the the airport’s immigration official but I do not know for sure.
I did however know that 8 days was not enough to explore Sarawak, nor would it get me to my (already booked) exit flight a month from its expiration.
Extending Your Malaysian Visa in Kuching
Extending your visa in Kuching is a simple process that took me all of a half-hour.
You go to the immigration office (Tingkat 1 & 2, Bangunan Sultan Iskandar Jalan Simpang Tiga 93550 Kuching, Sarawak) on the second floor of the immigration building and explain your situation.
They give you a form.
You fill it out (it’s very simple but you need a Sarawak address …use your guest house’s address if you need to).
You Pay. It costs 50RM( ~$16) per month (I had the option of extending up to three months).
You get an extension.