month starting another day - mysql

Question

I've been using MONTH() function to get the months and grouping by month, like this example query.
SELECT
t1.ano,
t1.mes,
tempo_extra,
tempo_ativo,
tempo_extra / tempo_ativo AS volume_extra
FROM
(SELECT
YEAR(`data`) AS ano,
MONTH(`data`) AS mes,
SUM(tempo) AS tempo_extra
FROM
rh.aprovacoes
WHERE
(tipo = 'BH' OR tipo = 'HE')
AND estado = 1
AND YEAR(aprovacoes.`data`) = 2016
GROUP BY MONTH(`data`)) AS t1
LEFT JOIN
(SELECT
MONTH(`data`) AS mes, SUM(ativo) AS tempo_ativo
FROM
rh.processamento
GROUP BY MONTH(`data`)) AS t2 ON t1.mes = t2.mes
ORDER BY mes DESC;
How can i make months start on 23rd of the last month and end on 22nd of the current month.
For example, April starting on March 23rd and end on April 22nd.

Answer 1

Simply subtract 22 days from your date and add a month:
(`data` - interval 22 day) + interval 1 month
March 22 => February 28 or 29 => March 28 or 29
March 23 => March 1 => April 1
April 22 => March 31 => April 30
April 23 => April 1 => May 1
SQL fiddle: http://sqlfiddle.com/#!9/9eecb7d/54883
Your query joins records regardless of the year by the way. I don't think this is desired, so in below query I've corrected this.
SELECT t1.ano, t1.mes, tempo_extra, tempo_ativo, tempo_extra/tempo_ativo AS volume_extra
FROM
(
SELECT
YEAR(data - interval 22 day + interval 1 month) AS ano,
MONTH(data - interval 22 day + interval 1 month) AS mes,
SUM(tempo) AS tempo_extra
FROM rh.aprovacoes
WHERE (tipo = 'BH' OR tipo = 'HE')
AND estado = 1
AND YEAR(aprovacoes.data - interval 22 day + interval 1 month) = 2016
GROUP BY
YEAR(data - interval 22 day + interval 1 month),
MONTH(data - interval 22 day + interval 1 month)
) AS t1
LEFT JOIN
(
SELECT
YEAR(data - interval 22 day + interval 1 month) AS ano,
MONTH(data - interval 22 day + interval 1 month) AS mes,
SUM(ativo) AS tempo_ativo
FROM rh.processamento
GROUP BY
YEAR(data - interval 22 day + interval 1 month),
MONTH(data - interval 22 day + interval 1 month)
) AS t2 ON t1.ano = t2.ano AND t1.mes = t2.mes
ORDER BY t1.ano DESC, t1.mes DESC;