Date format for tine-tuning AI models

Hi. I’m struggling with the date format to use in my datasets to fine-tune QwenX.X and Gemma-X.X models. The models is always inferring the wrong dates after fine-tuning. I tried several formats as shown in the example below to no avail. I would appreciate any guidance regarding the right date format to use or how to discover it for a given model. Examples of date formats I test but none of them worked: user: When did XYZ work for ABC. Assistant: From January 2021 till December 2021. user: When did XYZ work for ABC. Assistant: From 01, 2021 till 12, 2021. user: When did XYZ work for ABC. Assistant: From 01-01-2021 till 12-01- 2021. user: When did XYZ work for ABC. Assistant: From 01-01-2021 till 12-01- 2021 . user: When did XYZ work for ABC. Assistant: From January 2021 01-01-2021 till December 2021 12-01- 2021 .