How can we calculate archivelog size each day?

How can we calculate archivelog size each day/hour?
This is not a difficult idea for someone who work as DBA, I just wish more idea for discussion and sharing . Some Idea using V$LOG.BYTES and V$ARCHIVED_LOG.*
but I believe V$ARCHIVED_LOG view be able to help:
Archivelog size each day:

SQL> select trunc(COMPLETION_TIME) TIME, SUM(BLOCKS * BLOCK_SIZE)/1024/1024 SIZE_MB from V$ARCHIVED_LOG group by trunc (COMPLETION_TIME) order by 1;

TIME SIZE_MB
---------- ----------
2011-02-12 71797.87
2011-02-13 75880.52
2011-02-14 73569.37
2011-02-15 76776.81
2011-02-16 73959.86
2011-02-17 69969.71
2011-02-18 74677.10
2011-02-19 75474.95
2011-02-20 77967.07
2011-02-21 67802.70

Archivelog size each hour:

SQL> alter session set nls_date_format = 'YYYY-MM-DD HH24';

Session altered.

SQL> select trunc(COMPLETION_TIME,'HH24') TIME, SUM(BLOCKS * BLOCK_SIZE)/1024/1024 SIZE_MB from V$ARCHIVED_LOG group by trunc (COMPLETION_TIME,'HH24') order by 1;

TIME SIZE_MB
------------- ----------
2011-02-21 00 6396.65
2011-02-21 01 2797.31
2011-02-21 02 2010.45
2011-02-21 03 1871.77
2011-02-21 04 1481.5
2011-02-21 05 2868.20
2011-02-21 06 2363.89
2011-02-21 07 4269.26
2011-02-21 08 2469.08
2011-02-21 09 3007.06
2011-02-21 10 3561.97
2011-02-21 11 2530.57
2011-02-21 12 3509.08
2011-02-21 13 3022.5
2011-02-21 14 3514.97
2011-02-21 15 4057.45
2011-02-21 16 3021.27
2011-02-21 17 4014.31
2011-02-21 18 4011.66
2011-02-21 19 4008.10
2011-02-21 20 3015.46

That is just my samples ^^
How about archive log size each of day/hour on RAC?- Using GV$ARCHIVED_LOG ???
SQL> select INST_ID, RECID, NAME, to_char(COMPLETION_TIME,'YYYY-MM-DD HH24:MI:SS'), ARCHIVAL_THREAD# , blocks * block_size from GV$ARCHIVED_LOG order by COMPLETION_TIME;
INST_ID RECID NAME TO_CHAR(COMPLETION_ ARCHIVAL_THREAD#
---------- ---------- -------------------------------------------------- ------------------- ----------------
4 258572 +ARCH/DB/4_73214_617849235.dbf 2011-02-21 20:29:52 4
2 258572 +ARCH/DB/4_73214_617849235.dbf 2011-02-21 20:29:52 4
1 258572 +ARCH/DB/4_73214_617849235.dbf 2011-02-21 20:29:52 4
3 258572 +ARCH/DB/4_73214_617849235.dbf 2011-02-21 20:29:52 4
1 258573 +ARCH/DB/1_55739_617849235.dbf 2011-02-21 20:44:22 1
3 258573 +ARCH/DB/1_55739_617849235.dbf 2011-02-21 20:44:22 1
4 258573 +ARCH/DB/1_55739_617849235.dbf 2011-02-21 20:44:22 1
2 258573 +ARCH/DB/1_55739_617849235.dbf 2011-02-21 20:44:22 1

NO!!! - What do we see? - When we want to calculate archivelog size on RAC, we just use V$ARCHIVED_LOG view. So, on RAC:
Archivelog size each day:

SQL> select trunc(COMPLETION_TIME) TIME, SUM(BLOCKS * BLOCK_SIZE)/1024/1024 SIZE_MB from V$ARCHIVED_LOG group by trunc (COMPLETION_TIME) order by 1;

TIME SIZE_MB
---------- ----------
2011-02-12 71797.87
2011-02-13 75880.52
2011-02-14 73569.37
2011-02-15 76776.81
2011-02-16 73959.86
2011-02-17 69969.71
2011-02-18 74677.10
2011-02-19 75474.95
2011-02-20 77967.07
2011-02-21 67802.70

Archivelog size each hour:

SQL> alter session set nls_date_format = 'YYYY-MM-DD HH24';

Session altered.

SQL> select trunc(COMPLETION_TIME,'HH24') TIME, SUM(BLOCKS * BLOCK_SIZE)/1024/1024 SIZE_MB from V$ARCHIVED_LOG group by trunc (COMPLETION_TIME,'HH24') order by 1;

TIME SIZE_MB
------------- ----------
2011-02-21 00 6396.65
2011-02-21 01 2797.31
2011-02-21 02 2010.45
2011-02-21 03 1871.77
2011-02-21 04 1481.5
2011-02-21 05 2868.20
2011-02-21 06 2363.89
2011-02-21 07 4269.26
2011-02-21 08 2469.08
2011-02-21 09 3007.06
2011-02-21 10 3561.97
2011-02-21 11 2530.57
2011-02-21 12 3509.08
2011-02-21 13 3022.5
2011-02-21 14 3514.97
2011-02-21 15 4057.45
2011-02-21 16 3021.27
2011-02-21 17 4014.31
2011-02-21 18 4011.66
2011-02-21 19 4008.10
2011-02-21 20 3015.46

How about your idea?