Untitled

public async Task<bool> HasTimeEntryForTodayAsync(string instructorId, string subjectCode)
{
    var today = DateTime.Today;
    var timeEntries = await _firebaseClient
        .Child("TimeEntries")
        .OrderBy(nameof(TimeEntry.instructorId))
        .EqualTo(instructorId)
        .OnceAsync<TimeEntry>();

    return timeEntries.Any(entry =>
        entry.Object.SubjectCode == subjectCode &&
        entry.Object.TimeIn.Date == today);
}