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'''Author''' : Daniel Lea

'''ticket''' : #1310

'''Branch''' : [https://forge.ipsl.jussieu.fr/nemo/browser/branches/2014/dev_r4650_UKMO7_STARTHOUR      dev_r4650_UKMO7_STARTHOUR ] 
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=== Description ===

NEMO is hard-wired to always start a run at the start of the day (at 0z). I propose to extend the option of setting the start date to allow for the setting of a start hour via a namelist option.

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=== Testing ===
Testing could consider (where appropriate) other configurations in addition to NVTK].

||NVTK Tested||YES||
||Other model configurations||ORCA2, AMM12||
||Processor configurations tested||All the standard SETTE tests||
||If adding new functionality please confirm that the [[BR]]New code doesn't change results when it is switched off [[BR]]and !''works!'' when switched on||YES||

(Answering UNSURE is likely to generate further questions from reviewers.)

'Please add further summary details here'

 * The code passes all SETTE tests (at r5072 of the trunk)
 * If starthour=0 then results of SETTE test results don’t change
 * AMM12 is restartable with starthour=6 and all write statements indicate that correct forcing files are being read in to the model. AMM12 includes tides and these was the hardest bit to get right (but it now works!)


=== Bit Comparability ===
||Does this change preserve answers in your tested standard configurations (to the last bit) ?||YES||
||Does this change bit compare across various processor configurations. (1xM, Nx1 and MxN are recommended)||YES||
||Is this change expected to preserve answers in all possible model configurations?||YES||
||Is this change expected to preserve all diagnostics? [[BR]]!,,!''Preserving answers in model runs does not necessarily imply preserved diagnostics. !''||YES||

If you answered !'''NO!''' to any of the above, please provide further details:

 * Which routine(s) are causing the difference?
 * Why the changes are not protected by a logical switch or new section-version
 * What is needed to achieve regression with the previous model release (e.g. a regression branch, hand-edits etc). If this is not possible, explain why not.
 * What do you expect to see occur in the test harness jobs?
 * Which diagnostics have you altered and why have they changed?Please add details here........

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=== System Changes ===
||Does your change alter namelists?||YES||
||Does your change require a change in compiler options?||NO||

If any of these apply, please document the changes required here.......

There is an additional namelist variable nn_time0 in namrun namelist which is used to specify the start hour for the run.

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=== Resources ===
!''Please !''summarize!'' any changes in runtime or memory use caused by this change......!''

None

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=== IPR issues ===
||Has the code been wholly (100%) produced by NEMO developers staff working exclusively on NEMO?||YES||

If No:

 * Identify the collaboration agreement details
 * Ensure the code routine header is in accordance with the agreement, (Copyright/Redistribution etc).Add further details here if required..........