CREATE TABLE table_22123920_4 (dates__mdy_ VARCHAR2, gross_sales VARCHAR2)

Which specific dates encompass the time period when 'The Show Girl Must Go On' showed a gross sales figure total of $2,877,906?
SELECT dates__mdy_ FROM table_22123920_4 WHERE gross_sales = "$2,877,906"
SELECT "dates__mdy_" FROM "table_22123920_4" WHERE "$2,877,906" = "gross_sales"