When it’s time to buy another desk calendar, it’s also time to witness the annual assault on the tax saving grace that is Proposition 13.

For 44 years, the voter-approved Prop. 13 protection against exorbitant property tax hikes has frustrated tax-and-spend bureaucrats and politicians and shined among the Golden State’s few reasonable policies — the kind that don’t repel productive people and business elsewhere.

Jon Coupal, president of the Howard Jarvis Taxpayers Association — named for the visionary responsible for Prop. 13 — published a recent message on the nonprofit’s newsletter that really nails the motivation behind anti-Prop. 13 efforts.

“Every argument … boils down to one thing: Control,” he wrote. “They may mask it in buzzwords like ‘economic dynamism’ and ‘equity,’ but the reality is that they think they know how to spend your money and use your land better than you do.”

Along with a direct cap on property taxes, Prop. 13 also brought us voting thresholds that make it harder to enact other taxes.

For that, Prop. 30 wears a permanent bullseye. And here is the latest threat, as outlined by Dan Walters in his CalMatters column this week:

“One potential clash this year is Gov. Gavin Newsom’s proposed financial penalties on oil companies that exceed still-to-be-specified limits on their profits. He initially proposed a tax on those profits, but a tax would require a two-thirds legislative vote, so Newsom substituted financial penalties which, at least theoretically, would require only a simple majority vote.”

Walters goes on: “However, the petroleum industry is branding the penalties as a tax, hinting that if Newsom’s measure becomes law, a legal challenge will be mounted on its constitutionality.”

Prop. 30 has survived many attempts to peel back protections, but it will never stop. A key battleground will be the ballot box.

Koupal capped off his column:

“If someone calls or knocks on your door and asks if you would be willing to support ‘reforming’ Prop. 13, remember what they are really asking: How much do you have and how fast can we have it?”