Help to Improve Spreadsheet Formula

[cyliyu]

I Need help in my spreadsheet to improve the formula.

1) How to make column "J" to display "" if no data was input?
2) How to compute the no of serviceable days base on the following condition:-
(a) If empty date input in the Removed Date in column N, calculate the serviceable days in column R based on today date - installed date in column H.
(b) If a date was input in Removed Date in column N, calculate the serviceable days in column R based on Removed Date in Column N - the Installed Date in Column H.

Thanks.

 

[cyliyu]

Not sure is this formula good or there are more improvement needed.
For Q1, I used

=IF((I2)="","",IF((I2)="N.A","N.A","Train "))&IFERROR(ROUNDUP((RIGHT(I2,2))/2,0),"")

For Q2, I used

=IF(H2="","",IF(N2="",TODAY()-H2,N2-H2))