Do I need to provide proof of funds on the day of my visa renewal application for retirement in Thailand?

My office require statements dated on the day of application. The statement and bank book also need to show a transaction on the day. I usually do a phone top up in the bank. Its not a bad idea to ask your office to write down in thai exactly what they require.

That is what you need to ask your local immigration office. Some accept bank letters up to 7 days old such as Bangkok, some offices accept letters dated only the day of application. Others are in-between.

For the transaction record, many accept those issued in advance (as some branch needs time to make a whole 1-year record), with your updated passbook on the day of application (<- that should have records after issuance of the 1-year transaction)