class DuckDB::PreparedStatement

def bind_time(index, value)

# stmt.bind(1, '07:39:45')
# or you can specify time string.
stmt.bind(1, Time.now)
stmt = PreparedStatement.new(con, sql)
sql ='SELECT name FROM users WHERE birth_time = ?'
con = db.connect
db = DuckDB::Database.open('duckdb_database')
require 'duckdb'

The second argument value is to expected time value.
The index of first parameter is 1 not 0.
The first argument is index of parameter.
binds i-th parameter with SQL prepared statement. 
def bind_time(index, value)
  time = _parse_time(value)
  _bind_time(index, time.hour, time.min, time.sec, time.usec)
end