amocrm/internal/workers/data_updater/timer.go

package data_updater

import (
	"time"
)

func calculateTime() int64 {
	now := time.Now()

	targetTime := time.Date(now.Year(), now.Month(), now.Day(), 4, 0, 0, 0, now.Location())
	if now.After(targetTime) {
		targetTime = targetTime.AddDate(0, 0, 1)
	}

	toTarget := targetTime.Sub(now)
	sec := toTarget.Nanoseconds()

	return sec
}