Agreed if the output is a 30 day vector. I assumed it was a single valued output. For example, the stock trading price of google will be x in 30 days vs the closing price of google will be (y1,y2,…y30). Not sure what @Zarkaylia is looking for.
For single valued design, you should  be able to just retrain the model for that one value. If it’s a vector spanning 30 days then you will need to change the final layer’s output to 30 units. For this case, you might want to test trying out a LSTM model too.
At least that is how I am currently understanding the problem. Hopefully it’s helpful.