use seq(), not seq.Date() in tests (#5222)
use seq(), not seq.Date() in tests (#5222)


jangorecki/data.table,vlulla/data.table,jangorecki/data.table,vlulla/data.table,Rdatatable/data.table,Rdatatable/data.table,vlulla/data.table,Rdatatable/data.table,jangorecki/data.table,Rdatatable/data.table,jangorecki/data.table,vlulla/data.table