for better readability, and to silence following warning
from Clang 17:
```
/home/kefu/dev/scylladb/utils/date.h:5965:25: error: result of comparison of constant 9223372036854775807 with expression of type 'int' is always true [-Werror,-Wtautological-constant-out-of-range-compare]
Y <= static_cast<int64_t>(year::max())))
~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/kefu/dev/scylladb/utils/date.h:5964:57: error: result of comparison of constant -9223372036854775808 with expression of type 'int' is always true [-Werror,-Wtautological-constant-out-of-range-compare]
if (!(static_cast<int64_t>(year::min()) <= Y &&
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~
```
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
as one of its member variable does not have default constructor.
this silences following warning from Clang-17:
```
/home/kefu/dev/scylladb/utils/date.h:708:5: error: explicitly defaulted default constructor is implicitly deleted [-Werror,-Wdefaulted-function-deleted]
year_month_weekday() = default;
^
/home/kefu/dev/scylladb/utils/date.h:705:27: note: default constructor of 'year_month_weekday' is implicitly deleted because field 'wdi_' has no default constructor
date::weekday_indexed wdi_;
^
```
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
We need 64-bit year and days representation to support the boundary
values of the CQL data type, which is implemented using Joda Time
library's DateTime type.
