Cursor/Dynamic SQL to execute Postgres Procedure

I have a Postgres procedure that aggregates some data from a table and puts the results in a different table for display on a PowerBI report. The procedure aggregates the data on a daily basis, so accepts a startDate and endDate parameter (where endDate is always startDate + 1).

CREATE OR REPLACE PROCEDURE schema.DailyCalculation(
    "startDate" timestamp without time zone,
    "endDate" timestamp without time zone)
AS $$
DECLARE
   -- some declarations 
BEGIN
   -- do some stuff
END;
$$ LANGUAGE plpgsql;

I've now identified an error in the way we calculated data in the past, and want to call this procedure for a date range. To break it into manageable chunks, I still want to call DailyCalculation for a single day period, but create a new procedure that I can provide with a longer date range that will repeatedly call DailyCalculation with only single day ranges in that date range.

For arguments' sake, I want to recalculate January 2023. So, I want to call something like:

CALL schema.RecalculateDailyData('2023-01-01', '2023-01-31');

which I want to effectively do the following:

CALL schema.DailyCalculation('2023-01-01', '2023-01-02');
CALL schema.DailyCalculation('2023-01-02', '2023-01-03');
CALL schema.DailyCalculation('2023-01-03', '2023-01-04');
...
CALL schema.DailyCalculation('2023-01-30', '2023-01-31');

I've been able to generate a query that would generate dynamic SQL to this effect:

SELECT CONCAT('CALL schema.DailyCalculation(''', date_trunc('day', dd)::date, ''', ''', date_trunc('day', dd)::date + 1, ''');') FROM generate_series( '2023-01-01'::timestamp, '2023-01-31'::timestamp, '1 day'::interval) dd;

How do I iterate through this resultset, and execute the dynamic SQL query?

You can use the function generate_series() to create each date of interested and call your procedure in a for loop.

create or replace procedure DailyCalculation(
                  startdate  timestamp without time zone 
                , enddate    timestamp without time zone
                )
   language plpgsql
as $$
declare
   -- some declarations 
begin
   insert into demo(routine_name, start_date, end_date)
        values ('Procedure:DailyCalculations', startdate,enddate); 
end;
$$;

-- DO block to call DailyCalculations
do $$
declare 
    sdt record; 
begin
    for sdt in (select dt 
                  from generate_series ( '2023-01-01'::timestamp
                                       , '2023-01-31'::timestamp
                                       , interval '1 day' 
                                       ) gs(dt)
               )
    loop 
        call DailyCalculation(sdt.dt, sdt.dt+interval '1 day');
    end loop;
end;
$$; 

Alternatively you can create a Function (returns Null) instead of a Procedure and accomplish this with a single query.

create or replace function DailyCalculation_fn(
                  startdate  timestamp without time zone 
                , enddate    timestamp without time zone
                )
    returns void    
   language plpgsql 
as $$
declare
   -- some declarations 
begin
   insert into demo(routine_name, start_date, end_date)
        values ('Function DailyCalculation_fn', startdate,enddate); 
end;
$$; 

select DailyCalculation_fn(dt, dt+interval '1 day') 
  from generate_series ('2023-01-01'::timestamp
                       , '2023-01-31'::timestamp
                       , interval '1 day' 
                       ) gs(dt);

The alternative function however does rely side effects and is sometimes considered inappropriate for that reason.

See demo for each here. For demo both just insert into a demo table.

NOTE: You specified tour procedure needs 2 parameters, startDate and endDate, but then declare that end date is always be start+1. If this is required, why pass enddate just let your procedure/function calculate the end date. That way you ensure the end date is always correct. What does your Procedure do when startDate+2 or startDate+10 or anything other than startdate+1 is passed.