convert single or double digit number to 2 digit month

Question

I have months listed in a column as single digits representing the month of the year as shown here below.  To be consistent with other files I am joining this data to, I need to combine these with a year column and add a leading zero only when it is a single digit month as sown in the update (i.e. "07" from "7" for July).  Can anyone help me to do this?  I've tried several methods unsuccessfully to even produce the month numbers with a leading zero, without the leading zero also on the 10-12th months (010,011,012) let alone combining the year and month fields as shown her as "Period".  Any help would be greatly appreciated.

CurrentUpdateYearmonthmonthPeriod20191012019-0120192022019-0220193032019-0320194042019-0420195052019-0520196062019-0620197072019-0720198082019-0820199092019-09201910102019-10201911112019-11201912122019-12

patrick_digan · Accepted Answer

padleft(tostring([month]),2,"0") should add the leading 0 when necessary. then [Year]+"-" + [Month] would get your period field. If the data types aren't correct, you can use tostring and tonumber to convert between strings and numbers..