Many times the Unix Epoch Time gets stored in the database. But this is not very human readable and conversion is required for reports and dashboards.
Example of Unix Epoch Time:
1529853245
Presto provides many date time functions to help with conversion.
How to Convert Epoch Time to Date in SQL?
In case of a Unix Epoch Time, the from_unixtime function can be used to convert the Epoch time. After converting the Unix Epoch time to a timestamp, you can cast it into other formats as needed such as extracting just the date. Examples follow below.
The from_unixtime function returns a timestamp.
from_unixtime(unixtime) → timestamp
Returns the UNIX timestamp unixtime as a timestamp.
Examples:
Query
select from_unixtime(1529853245) as timestamp;
Result
timestamp
2018-06-24 15:14:05.000
Query
select cast(from_unixtime(1529853245) as date) as date;
Result
date
2018-06-24
More examples and information can be found here: https://ahana.io/answers/how-to-convert-date-string-to-date-format-in-presto/