Co-ownership of a shared asset can be a great way to reduce costs and maximize usage. However, scheduling can be a challenge, especially if there are different co-owners with different preferences and availability.

Here are some different scheduling types that can be used for co-owners to manage their shared asset:

1. Lottery Schedule:
   A lottery schedule involves randomly selecting dates for each person or group to use the shared object. This can be done through a lottery system, where each person or group is assigned a number, and dates are randomly assigned to each number. This type of scheduling can ensure that everyone has an equal chance of using the vacation house during peak times.

2. Fixed Time:
   This scheduling type involves assigning specific time periods, such as every Sunday, every 5th week, or every February, to each co-owner. This type of scheduling may involve co-owners paying higher prices for preferred time slots. Fixed time schedules can be ideal for co-owners who want to plan their usage in advance and prefer a set schedule that doesn't change.

3. Fixed Time with Offset:
   This scheduling type is similar to fixed time scheduling but with an offset, providing the opportunity for participants to experience different times of the periods.
   For example: using an offset of 1 week, a participant may be randomly assigned the 51st week of the current year. The following year, their schedule would shift to 52nd week, and in the subsequent year, it would shift to 1st week.

4. Priority Scheduling:
   This scheduling type is based on the principle that the co-owner who bought into the asset at a higher price will get a priority to pick the time. This type of scheduling is ideal for co-owners who want to ensure that the person who invested more gets more usage of the asset.
   There is typically a deadline for each participant to make their selection, such as a three-day window. The next person in line must make their choice three days after the previous person has made theirs.

5. Priority Scheduling with Offset:
   This scheduling type is similar to priority scheduling but with an offset, such as everyone paying the same but getting a different Priority each period. This type of scheduling ensures that everyone has an equal chance to choose their preferred time slot over time.
   For example, using an offset of 2, a participant may be randomly assigned a priority of 49 in the current year. The following year, their priority would shift to 51, and in the subsequent year, it would shift to 1.

6. As Needed / First Come, First Served:
   This scheduling type allows co-owners to reserve the asset on a first-come, first-served basis using an online calendar, such as Google Calendar or Apple Calendar.This type of scheduling can be ideal for co-owners who have different preferences and schedules that can change over time.

7. Agreement from Time to Time:
   This scheduling type involves regular discussions and agreements among co-owners to ensure that everyone gets a fair share of the asset.
   For example, co-owners can discuss and agree on the schedule at the beginning of the week, month, or year, based on their preferences and availability.

8. Point-Based Scheduling:
   This scheduling type involves assigning a certain number of points to each co-owner every periods, and each time slot of the period has a point value associated with the usage of the asset. Co-owners can use their points to book the asset for a certain period of time, with the length of time determined by the point value of that particular week.
   For example, a high season week might be worth more points than a low season week.

9. Combination of Above:
   A combination of the above scheduling types can also be used, such as randomizing the priority scheduling every year to ensure fairness or using a fixed schedule with an offset.

When a group of people time share a house, a boat, a car or anything together, there may be occasions where there are leftover time slots that have not been claimed by any of the participants. It's important to have a plan in place for what to do with this unused time, to ensure that it doesn't go to waste.

Here are some options to consider:

1. Put it on Short Term Rental Website:
   If the group has no use for the extra time, they can list it on short term rental website, such as Airbnb and try to rent it out to other travelers. This can be a great way to recoup some of the costs of the time share, and even make a profit.

2. Sell the unused time to one of the current owners:
   Sell the unused time to one of the current owners rather than selling to outside parties. This approach can be beneficial since there are no fees involved, and the selected owner is a trusted individual who is already invested in taking care of the house.

3. Assign it to one of the current owners:
   The group can randomly assign the leftover time to individuals who haven't had a chance to use the time share yet, or who have used it less frequently than others. Alternatively, they could assign the leftover time to those who are closest to the existing reserve time, or to those who have low season weeks.

4. Make repairs or upgrades:
   If the time share property is in need of repairs or upgrades, the group can use the leftover time to get these tasks done. This will improve the property for everyone, and make it more enjoyable to use in the future.

5. Donate it:
   If the group is unable to use the leftover time themselves, they can consider donating it to a charitable organization or a family in need. This can be a great way to give back to the community and make a positive impact in someone's life.

Regardless of what the group decides to do with the leftover time, it's important to have open communication and consensus among all the participants. This will help ensure that everyone is on the same page and feels comfortable with the decision that is made.