Listening Well is the Best Advice
Your time line will depend upon that of your primary international partner. The tricky part is that most substantial international programs have several partners -- for example, a local host institution that invites you to perform or teach, the local U.S. Embassy or Post that agrees to help you with funding and facilitative support, a corporation that is willing to provide cash or in-kind sponsorship, and/or a foundation that is interested in your mission and offers a grant.
It is quite likely that each of these entities has its own timeline and that adhering to one may bar you from meeting the deadline of the other(s).
When dealing with the State Department, there is a basic conundrum. Good projects have a year or two of planning behind them; but rarely can DOS officers concentrate on a project more than a few months beforehand, being completely consumed with day-to-day tasks and projects.
It has often been my experience that a cultural or public affairs officer will start up a conversation about a program a year or so in advance; but when I try to push the envelope forward, to get to the budget, program planning and grant execution stage, I cannot regain the person’s attention.
My advice is to listen carefully and get a sense of the operating style of the key person and/or department or Embassy and try to glean how much you need to conform to their way of working and/or how much you can exert your own sense of timely practice into the collaboration.