Short answer. Yes. Article 1784 sets the default rule that a partnership begins from the moment the contract is executed, but that default applies only unless the partners otherwise stipulate. So partners are free to agree, in the contract itself, that the partnership will begin on a later date instead.
What the law says
A partnership begins from the moment of the execution of the contract, unless it is otherwise stipulated.
Civil Code, Article 1784 — When a Partnership Begins. Read the full provision →
The default: partnership begins at execution
Article 1784 states a short, direct default rule: a partnership begins from the moment of the execution of the contract, unless it is otherwise stipulated. On its own, this default ties the start of the partnership to the act of signing — the moment the partners execute the contract that creates the partnership is, absent any different agreement, treated as the moment the partnership itself comes into existence. That default matters because a great deal can turn on exactly when a partnership begins, including when the duties partnership law imposes on the partners toward each other start to run.
Why 'unless it is otherwise stipulated' matters
That closing phrase is what makes the rule a default rather than a fixed requirement. A stipulation is simply a term the partners agree to and write into the contract, and the article expressly allows the partners to displace the moment-of-execution rule with whatever different starting point they prefer. Nothing in the text limits what kind of alternative stipulation is allowed, so the default rule steps aside whenever the partners have actually agreed, in the contract, to a different commencement date.
What agreeing to a later date actually changes
Agreeing to a later start date changes when the partnership itself is understood to exist for the purposes the law attaches to that moment, even though the contract creating it was executed earlier. In practice, this lets partners sign a partnership agreement today while setting the partnership's actual commencement for a future date specified in that same agreement — for instance, to align the start with a permit, a lease, or simply a date the partners find more convenient to begin operating together.
What doesn't change: the contract's own validity
What a later stipulated start date does not affect is whether the contract itself was validly executed. Article 1784 is concerned only with the moment the partnership 'begins,' not with the separate question of whether the contract satisfies whatever formal requirements apply to a valid partnership agreement. Signing on one date and stipulating a later commencement date are two different things under this article, and it is only the commencement date that the stipulation actually controls.