Standardize Dates in Text Dataset

I have a spreadsheet containing roughly 100-500 rows of text-based information; the only issue is that the dates appear in multiple styles (12/5/23, 05-Dec-2023, 2023.12.05, and so on). I need every date brought to one coherent format throughout the file—preferably ISO (YYYY-MM-DD), but I’m open to a different convention if you explain the benefit.

The job is purely text data cleaning: no duplicate removal or spell-checking is required, just precise format standardization. Once finished, send back the cleaned file plus a quick before-and-after sample so I can confirm the change. A short note on any edge cases you spotted would also be helpful.