date.c: Fix type missmatch warings from msvc
Fix compiler warings from msvc in date.c for value truncation from 64
bit to 32 bit integers.
Also switch from int to size_t for all variables with result of strlen()
which cannot become negative.
Signed-off-by: Sören Krecker <soekkle@freenet.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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