I just wanted to share an update after visiting both Malaysia (ML) and Singapore (SG). Thankfully, we didn't require any visas, and there were no associated visa costs. However, we did need to complete the Malaysia Digital Arrival Card (MDAC) form online, which is short and should be submitted only before 3 days of your arrival.
We spent our first week in ML before traveling to SG for another week. Upon returning from SG to ML by bus, we were required to complete the MDAC form again.
Here's a learning experience for others: Our bus from SG departed at approximately 9:30 PM and arrived at the ML immigration department around 11:05 PM that same day (before midnight). While this meant entering ML on the same day, I had filled out the MDAC form with an expected arrival date for the following day. Essentially, I arrived in ML an hour earlier than stated on my form. The immigration officer requested the MDAC, but thankfully, he understood that we were a family and simply advised us not to repeat the mistake in the future before allowing us to enter.
I wanted to share this experience so others can avoid making the same mistake.