How to fill missing dates (NaT) with the next date ?

My table looks like :

ID Amount Date

12 100 Jan-2020

12 400 NaT

12 100 NaT

12 500 NaT

12 100 NaT

14 900 Jan-2020

14 100 NaT

14 500 NaT

I need to fill the missing dates with the following month-year from the previous:

ID Amount Date

12 100 Jan-2020

12 400 Feb-2020

12 100 Mar-2020

12 500 Apr-2020

12 100 May-2020

14 900 Jan-2020

14 100 Feb-2020

14 500 Mar-2020

I tried using fillmissing, within each group, but doesn't work:

T2 = varfun(@(x) fillmissing(x,'linear'), T1,'groupingvariables',{'ID'},'InputVariables',{'Date'});

Answer 1

[Image Analyst]

I'd just run down the column and detect if the value is a NaT. If it is, replace it by the last good month plus 1. Attach your table if you need more help.