For each element in the Function input schema tree, you can specify a constant. Constants can be strings or numeric values. To specify a string, enclose the string in quotes. To specify a number, type the number into the schema element’s mapping field. The following illustrates specifying the string "USA" for the
Country item and 94304 for the
PostalCode item of a function input schema.

In constant expressions used in bindings, datetime values are read in according to the ISO 8601 standard, as described in the XML Schema specification. For example, the value:
If no timezone field is present, the value is interpreted in the timezone of the machine that is performing the parsing. This can lead to complications if you are processing data from different timezones, so you are encouraged to always use timezones.