Not sure if this helps... and it may be slightly overkill for what you are trying to achieve...
but i find this link and this master calendar creation process that Richard pearce created some time ago for qlikview but equally works well for Qlik Sense. it cantake some getting used to, / setting up against your qlik model. but once in, its extremely useful and fast to compare periods
attached is the qlikview (with explanations and pages laid out to explain what its doing). version (can be adapted screens to run on qlik sense), but have also attached the .qvf that i have converted to use this but just needs importing, reloading and playing with... can use this to do as little or as much as you want, including from and to dates 🙂
it makes comparing mtd, prev months, prev month prev year etc very easy in the long run with a simple flag and needs to be joined on your date field.
