This is only a rough overview of Juna's schedule, because I'm lazy (plus, there's always NPC Map Locations).

Mondays
900: leaves her cave and walks to town, does ballet east of the Community Center
1710: arrives at Robin's
1930: leaves Robin's and walks back to the forest, stands near her cave
2400: returns to her cave to sleep

Tuesdays
800: leaves her cave and walks to the Library
1600: arrives at the ladies' aerobics class
1810: walks back to the forest, stands outside the Wizard's tower
2200: returns to her cave
2400: goes to sleep

Wednesdays
900: leaves her cave and walks to town, stands on the bridge near Joja
1430: stands in front of the Community Center
1700: sits behind the playground
2100: walks back to her cave
2400: goes to sleep

Thursdays
930: leaves her cave and walks to the Library
1600: leaves the Library and walks to the Saloon
2200: walks back to her cave and goes to sleep

Fridays
930: leaves her cave to stand outside the Wizard's tower
1200: walks over to stand in front of the Travelling Merchant
1500: walks to the Hat Mouse and does ballet
2200: returns to her cave
2400: goes to sleep

Saturdays
1030: leaves her cave and walks to town, does ballet east of the Community Center
1720: arrives at Robin's, hangs out with Robin in her kitchen
2030: walks back to her cave and goes to sleep

Sundays
1000: leaves her cave to sit and scheme in front of the Wizard's tower
1320: heads inside the tower, stands by the cauldron
1600: sits at the back of the tower and schemes (or in the front if SVE is installed)
1900: stands by the Wizard's floor drawing
2300: returns to her cave and goes to sleep

Summer 5
930: leaves her cave and stands outside the Wizard's tower
1200: walks over to stand in front of the Travelling Merchant
1700: arrives at the Saloon to meet up with Robin and Demetrius
2100: walks back to her cave
2400: goes to sleep

Winter 16
1000: sits next to her bed inside her cave
1800: arrives at the beach, remains standing close to the beach exit
2100: walks back to her cave and goes to sleep

Winter 17
1100: arrives at the Wizard's tower, stands in the back room (or basement if SVE is installed)
1600: sits by the Wizard's floor drawing
1900: stands by the cauldron
2300: returns to her cave and goes to sleep

Summer 18
950: arrives at the Clinic to keep Robin company
1330: leaves the Clinic and walks to the Saloon
2000: walks back to her cave
2330: goes to sleep

3rd of every month at 6+ hearts
730: leaves her cave and walks to the women's locker room inside the Spa
1700: leaves the Spa to go stand in front of the Community Center
2100: walks back to her cave and goes to sleep

23rd of every month
900: stands next to her bed inside her cave
1050: leaves her cave and walks over to the big tree near the exit to the farm
1600: arrives at the ladies' aerobics class
1810: walks back to the forest, stands outside the Wizard's tower
2200: returns to her cave
2400: goes to sleep

Rain (50% chance)
1000: leaves her cave to do ballet below the Wizard's tower
1500: walks a little to the east to "recharge"
1800: walks to the end of the pier over the forest pond
2200: returns to her cave and goes to sleep

Rain 2 (50% chance)
800: leaves her cave and walks to the beach to do ballet
1800: walks closer to the water's edge
2200: walks back to her cave and goes to sleep