How to write and spell dates including a Month and Time in a sentence
Almost all resources split sentences by only month, only time and only a day. How can I say a sentence containing a month/date and a time in AmE, for example:
I'm arriving ... Jan 13, 20:11 ...
Are you available ... tomorrow at 11:33...
I'll be off ... May 1, 9:50...

Question

Answer

No preposition if you use "tomorrow".

The other examples refer to a day, so you use "on" (yes, I realise the next word after "on" is a month, but we still use that preposition).  You still put "at" before the clock times.

Answer

I am arriving on January 31st at 8:11 am/pm
Tomorrow, are you available at 11:30 ? or Are you available at 11:33?
I'll be off on May 1st

Answer

① I'm arriving at 20:11 on Jan 13.
②Are you available ... tomorrow at 11:33...( Or are you available ... at 11:33 tomorrow)
③I'll be off ... at 9:50, (on) May 1, ...