Understanding the zip file names

Hi,
I’d like to keep 2 months worth of monthly backups. In the job settings in the “To folder” tab, I can choose the maximum number of files in the folder. Is this how I keep 2 months worth of backups? If so, how do I interpret “number of files”? I see these files, for instance in my backups:

April 1, 2021 at 12:11 pm	2021-04-01_08-27-33_MMPJ4AWZ03.zip.EuXYf5
April 1, 2021 at 12:19 pm	2021-04-01_08-27-33_MMPJ4AWZ03.zip
April 1, 2021 at 12:19 pm	2021-04-01_08-27-33_MMPJ4AWZ03.zip.RUSR5a
April 1, 2021 at 12:27 pm	2021-04-01_08-27-33_MMPJ4AWZ03.zip.Iey5aN
May 1, 2021 at 6:16 am	2021-05-01_03-00-06_QQPJ4ASD02.zip
May 1, 2021 at 6:16 am	2021-05-01_03-00-06_QQPJ4ASD02.zip.6m871Y
May 1, 2021 at 6:25 am	2021-05-01_03-00-06_QQPJ4ASD02.zip.qDAT94
June 1, 2021 at 6:43 pm	2021-06-01_03-01-12_QMPJ4AVK02.zip

For June, there is one file, but for May and April there are multiple files and I suspect, by the timestamp and hash that these zip files are related. If I say “2 files” to be kept in the folder to represent 2 months, would that work or would I just get partial backups in a multi-part zip backup?

Thanks for any clarification you can give.