Use configured timezone throughout codebase

- Add config/timezone.go with timezone utilities:
  - SetDisplayTimezone(), GetDisplayTimezone()
  - Now(), Today() - current time/date in display TZ
  - ParseDateInDisplayTZ(), ToDisplayTZ() - parsing helpers

- Initialize timezone at startup in main.go

- Update all datetime logic to use configured timezone:
  - handlers/handlers.go - all time.Now() calls
  - handlers/timeline.go - date parsing
  - handlers/timeline_logic.go - now calculation
  - models/atom.go - ComputeUIFields()
  - models/timeline.go - ComputeDaySection()
  - api/plantoeat.go - meal date parsing
  - api/todoist.go - due date parsing
  - api/trello.go - due date parsing

This ensures all dates/times display correctly regardless
of server timezone setting.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/internal/api/todoist.go b/internal/api/todoist.go
index 2c94e08..6068d2e 100644
--- a/internal/api/todoist.go
+++ b/internal/api/todoist.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"time"
 
+	"task-dashboard/internal/config"
 	"task-dashboard/internal/models"
 )
 
@@ -287,9 +288,14 @@ func parseDueDate(due *dueInfo) *time.Time {
 	var dueDate time.Time
 	var err error
 	if due.Datetime != "" {
+		// RFC3339 includes timezone, then convert to display timezone
 		dueDate, err = time.Parse(time.RFC3339, due.Datetime)
+		if err == nil {
+			dueDate = config.ToDisplayTZ(dueDate)
+		}
 	} else if due.Date != "" {
-		dueDate, err = time.Parse("2006-01-02", due.Date)
+		// Date-only, parse in display timezone
+		dueDate, err = config.ParseDateInDisplayTZ(due.Date)
 	}
 	if err != nil {
 		return nil