I am trying to do currency conversion in a table. Where we have maintained two tables one for exchange rate and one in which foreign currency is there. Now the problem that we are facing is that only on some dates apply map is being applied for rest it is not being applied. Is this some limitation of apply map. Data size is large.
My best guess is that your numeric values in the map key does not match.
Date (today()) is not equal to Date(now()) even if their would look the same in the user interface. The numeric value of date(today()) is an integer, but fo| date(now()) it is a decimal containing hidden info about time of day.
Try to wrap dayname() around the lookup value in both transaction and map table to eliminate this problem.