And risk using these online encryption/decryption services who may save the results and steal funds as well? With my method you can do it by hand, you don't need any script.
Who said anything about online services?
You do trust your Operating System, right? Then just use the built-in tools. As easy as that.
I think it's you who didn't get it... With my method you don't have to rely on any external software or use online services (and risk theft) to decrypt anything, you can do it by hand. And with my method you can simply write down 12-24 BIP-39 words, not random gibberish 100-300 characters. The point is to write them down on a piece of paper, not store them on a computer in crypto.txt that my mother has access to and can simply copy-paste it. That's just extra risk right there.
You don't need any external software. You can just use your OS.
And you also don't need 100-300 gibberish character, it seems you still didn't get it. Just read my last 2 posts again. You can use
the same secret which in your case are a few dates.
No additional characters.
The difference is that you don't use a worthless and non-secure mechanisms which leaks the plaintext (your mnemonic code), but a
secure algorithm which is used all over the internet to secure messages.
If you don't trust AES, why don't you just use your stupid and insecure shift cipher to communicate with websites instead of TLS?
You have been warned. What you are doing is bad and insecure. And that is not an opinion, but a fact.
You gain almost zero usability but lose tons of security.
I understand that people who don't understand anything at all regarding security and cryptography believe to be able to create a secure mechanisms. Simply because they don't know better.
But the truth is, they can't. Believe it or not. We don't care whether you lose your money. The important part is that everyone else reading this knows that your mechanisms is insecure.