Problem with format

By default used system date format (Control panel > Regional settings)
But you can change date format using calculated field

Example:

strftime('%d/%m/%Y', datefield)

The following is a complete list of valid strftime() substitutions:

%d          day of month: 00 
 %f          fractional seconds: SS.SSS 
 %H          hour: 00-24 
 %j          day of year: 001-366 
 %J          Julian day number 
 %m          month: 01-12 
 %M          minute: 00-59 
 %s          seconds since 1970-01-01 
 %S          seconds: 00-59 
 %w          day of week 0-6 with Sunday==0 
 %W          week of year: 00-53 
 %Y          year: 0000-9999 
 %%          %

Also you can change Yes/No values using calculated field

CASE BoolField WHEN 1 THEN 'True' WHEN 0 THEN 'False' ELSE '' END

you can change words 'True' and 'False' to any other words.

OKay, so , i created a calculated field for my "boolean value" in this case i have 3, and i'll name them :

CASE Assistencia.taxaurg WHEN 1 THEN 'SIM' WHEN 0 THEN 'NÃO' ELSE '' END
CASE Assistencia.backup WHEN 1 THEN 'SIM' WHEN 0 THEN 'NÃO' ELSE '' END
CASE Assistencia.reincidencia WHEN 1 THEN 'SIM' WHEN 0 THEN 'NÃO' ELSE '' END

for now on, the reports will allways look at the fields "assistencia.taxaurgencia, backup and reincidencia" as SIM and NÃO right?

As for the strftime('%d/%m/%Y', datefield) , i added strftime('%d/%m/%Y', assistencia.data) and gave me an error.

i still want to send you my project since you didn't received it last time, but i want to change some fields to english so you can understand how the DB works.