Non-calendar-based tool to allocate people/resources?

I'm looking for a tool where I can do lightweight project planning. I want to allocate time for the team over the course of a month and quarter, but I don't want to do it as granularly as using a calendar. I currently use a spreadsheet for this. Each team member has N days in a month, and then we allocate those days to various projects, but not on particular dates. The spreadsheet has some formulas so you can see what % allocated people are, and what % each type of work gets (Feature Development, Marketing, Support, Unplanned Engineering, Ops Requirement Engineering). We use this to do OKR planning at the beginning of the quarter, and then from the OKRs we decide on tasks as a team, and then build the spreadsheet as a rough plan for the coming month and quarter. Is there a SaaS that does this well and lightly, without day-level calendars?