One of common tasks for OpenRefine is conversion of dates from String.
Conversion could be performed by toDate function.
Source data:
11-04-15 9:28 12-04-15 8:56
Open Edit cell – Transform for the column and type following GREL:
value.toDate("dd-MM-yy h:mm")
Result (in Date format):
2015-04-11T09:28:00Z 2015-04-12T08:56:00Z
Another example. Source data
11/04/2015 09:28:25 13/04/2015 08:56:57
GREL:
toDate(value, "dd/MM/yyyy hh:mm:ss")