Hi Luis,
If all you are looking for is a date then please consider the following...
1) Date value loaded as a number:

2) Divide the date value by 1000 and then apply the DateFormat() function:

Please refer to the following Help Centre page for a comprehensive view on available date formats:
- https://help.apptio.com/en-us/studio/formulas-and-functions/functions/dateformat.htm?Highlight=date%20format
Hope this helps and please let me know if you have any further questions.
Thanks Luis.
Alex.
#Platform