1.When and where are all the rival heart events for everyone except ann?

1.
Doctor:
Black:The clinic on Mon, Tue, or Wed, when Elli's heart color is black
Blue: Ellen's house on Monday between 9am and 7pm.
Green:Second year in the game, the Clinic on Thur between 9am and 7pm
Orange: 4th year,Mineral Beach on Wed between 7pm and 10pm

Gray
Black :Saibara's blacksmith shop between 10am and 1pm
Blue: Library between 1pm and 4pm when Gray's there.
Green: 2nd year in the game, walk up to the summit of Mother's Hill between 7am and 10am ( it has to be sunny)
Orange:4th year in the game, Library between 1pm and 4pm

Kai:
Black:Summer season only, Mineral Beach between 3pm and 4pm (it has to be a sunny day)
Blue: Summer season, Mineral Beach between 9am and 7pm on a Tues, Thur, or Sat.(it has to be sunny)
Green:Summer, after you have reached your 2nd year, Mineral Beach on a Sunday between 2pm and 4pm on a sunny day
Orange:Chicken Ranch in the Summer of your 4th year (between 11:30am and 4:00pm)

Rick:
Black:Leave the Spring Mine on a sunny Wednesday, Thursday, Friday or Saturday. The time must be between 11:00 am and 6:00 pm
Blue:walk out of Gotz's house on a sunny Sunday or Monday between the hours of 11am and 6pm
Green:2nd year, Goddess' Pond, go into the Spring Mine. When you exit you might trigger this event between the hours of 11am and 6pm on a sunny Wednesday or Friday
Orange:4th year, go into the Poultry Farm shop between 1pm and 4pm and then exit outside to start the event. Popuri has to be married (to either Kai or yourself)

If you want the girl and guy to get married, see all their rival events and one week later they're going to get married.

2. Unfortuanately there is no trick, you can only guess.
3.It takes 14 days for a baby cow to become a medium sized one, and a medium sized one becomes and adult in 7 days. If you had the baby cow born on your farm, then 21 days. If you bought it, 1 week.
4.You dog grows up on the last day of summer of your first year, or the first day of Fall.
5. You can buy the frisbee and ball from Won on the first day of fall in your first year.
6. In the winter dig in the winter mines to Floors 30, 70, 90, 110, 130, 170, 190, 255 to get pink diamonds, she loves them. Get lots of oil and a kitchen, get some chikens if you don't already have some, and cook scrambled eggs for her everyday. At the horse races get as many perfumes as you can hold, give her the perfumes. She basically likes food, here's some of her favorites: Egg dishes, Stew, Curry Rice, Strawberry Milk, Sandwitch, Sweets, Rice Cakes, Diamond, Pink Diamond, Perfume, and Truffle Rice.

7.
Ann's Heart events:
Black:Doug's Inn between 10:40am and 1pm
Purple:Second floor of Doug's Inn between 10am and 1pm on Wednesday, Thursday, Friday, or Saturday
Blue: Doug's Inn on Monday or Friday between noon and 7pm
Yellow: Doug's Inn on Wednesday, Thursday, Saturday, or Sunday between 10am and 7pm

Hope I helped.