I have a .txt file with a chat history that has date, sender and content. I successfully imported chat history to my Telegram using telethon and TLImporter (https://github.com/TelegramTools/TLImporter). It sends all messages with current time.
WhatsApp chat history import works properly with backward timestamp. I want to simulate my chat history as whatsapp chat history and then is it possible to import messages with the date they were sent and they should be shown in telegram in that dates (it is in .txt file and obviously conversation was in past)? If so, how?
It isn't possible to import messages via third party tools like the one you linked, as messages cannot be sent with a timestamp in the past.
Only Telegrams own tool can do this, as they can just set the message timestamp according to the import, but backdating isnt possible from the user.